Based on Gilia divaricata Torr. ex A.Gray, non Gilia divaricata Nutt. 1848.

Taprooted annual herbs to 15 cm tall and 20 cm wide, sometimes larger, often wider than tall. Primary stem erect, terminating in an inflorescence head 1–5 cm above the cotyledons; generally greatly exceeded by secondary stems, with tertiary, and quaternary stems present on larger plants (these higher order stems may be reduced in length and the inflorescence heads ± congested); higher order branches arise from axils of proximal inflorescence bracts, axils of leaves subtending the primary head, or less commonly, leaves within 1 cm of an inflorescence head; branches ascending to spreading and ± leafless, except for leaves subtending higher order branches or within 1 cm of a head; stem and branches tan to reddish-brown, glabrous or sparsely minutely glandular pubescent to glabrescent, less often villous, the trichomes generally less than 0.5 mm long. Cotyledons two, linear, entire, united at base. Leaves somewhat finely stipitate-glandular proximally, less so distally; leaves at the lowermost nodes opposite, linear-filiform, and widened at the point of stem attachment, the proximal nodes often congested with overlapping leaf bases. More distal leaves alternate, entire, or more commonly with 1–3 paired or unpaired linear lateral lobes 1–5 mm long attached along the proximal 3(–15) mm of the leaf, with an elongated, linear terminal segment. Inflorescences head-like, generally ≤ 10 mm diameter (exclusive of bract tips; ~15 mm with bract tips), mostly less than 15 flowered, villous proximally, obscurely glandular. Inflorescence bracts < 10(–13) mm long, ± palmatifid to subpalmatifid; outermost 1–2 bracts with a short achlorophyllous base and 2–3 pairs of lateral lobes flanking an elongate terminal lobe, the distal pair of lateral lobes sometimes shorter and reflexed somewhat out of plane relative to the other lobes; bract bases become larger and clasping centripetally with lateral lobes reduced to a single pair departing from near the apex of the bract base flanking the central terminal lobe, all bract lobes chlorophyllous, entire, long tapering acute. Bracts sparsely villous abaxially, more densely villous adaxially and proximally along the lobes just above their point of attachment, with the distal 1/2 of each lobe more or less glabrous or with a few minute stipitate glands. Flowers actinomorphic, calyces mostly 4.5–7.5 mm long, tube ~ 1.5–2 mm; costae entire, long tapering acute, strongly unequal to subequal with typically two costae longer than the other three; costae narrowing proximally, the shorter ones narrower at base than the intercostal membrane and the longer ones subequal with the membrane; calyx tube achlorophyllous, minutely glandular-puberulent on the intercostal membrane with the costae at least somewhat villous, the trichomes longest along the costae at the junction with the intercostal membrane, the free portion of the costae glabrous to very sparsely and minutely glandular distally; intercostal membrane v-shaped at sinus. Corolla generally shorter than longest calyx costae at anthesis but exceeding the calyx as fruit matures, narrowly funnelform, glabrous, 3.5–5.0 mm long, lobes 0.6–1.0 mm long × 0.4–0.9 mm wide, proximal tube white, distal tube and throat yellow, sometimes red-streaked, transitioning to white lobes suffused with pink or lavender at tips (drying pink); tube base expanding and investing the fruit apex. Stamen filaments unequal, 0.1–0.6 mm long, inserted unequally to subequally 0.2–1.0 mm below corolla sinuses, included in throat to slightly exserted; pollen white, apertures pantoporate, acolpate; sexine seimitectate, reticulate, heterobrochate. Ovary two-chambered, unequally three-valved with two values bearing a septum and the third valve smaller and lacking a septum entirely or nearly so, stigma obscurely three-lobed, minute, unequally divided with two stigmatic lobes nearly entirely fused, generally included in the corolla throat; capsules mostly 2–2.5 mm long, dehiscing circumcisally around the base with valves splitting upward loculicidally (completely) and septicidally (partially). Seeds generally 5–9(–12) per fruit, medium brown, ovoid-angular, mucilaginous when wet. Nuclear gene loci showing diploid PCR amplification patterns.

Navarretia divaricata occurs on a variety of soils from (800)1000–2600 meters in foothill and mountain habitats. It is widely distributed from Santa Barbara and Tulare Counties, California in the south to just within the borders of British Columbia, Canada, in the north, and east to Nevada and Idaho (Fig. 2). Flowering time is (May)June–July(September).

Navarretia divaricata has many occurrences throughout its broad range, and is typically abundant when encountered. Occurrences near the periphery of its range (e.g., in British Columbia) may be limited in numbers, but the species is otherwise well established. It is a species of Least Concern following IUCN (2012) Red List version 3.1 criteria.

From the Latin divaricatus, to spread or diverge at a wide angle, which aptly describes the characteristic repeated pattern of nearly leafless stems diverging from under flowering heads to give rise to additional, well-separated flowering heads in this species and its morphological allies.

Canada. British Columbia: Anarchist Mt., 1.6 km north of Hwy 3 rest stop, 6.5 km due east of Osoyoos Lake, 49.0275°N, 119.35°W, 1350 m, 10 July 2000, Lomer 3838 (UBC Scan); Anarchist Mt., 7 km due east of Osoyoos Lake, 1.5 km due southwest of summit, 200 m northeast of tower, 49.02658°N, 119.34786°W, 1380 m, 9 July 2013, Lomer 8435 (UBC scan).

United States of America. All seventeen specimens cited by Jepson (1943) under Navarretia divaricata var. divaricata (JEPS); California: Alpine County, North side of Hwy 88 along an old dirt road, 38.7240°N, 119.9542°W, 2262 m, 10 July 2014, Johnson 14-179 (BRY); Amador County, down slope from Tragedy Springs Monument, 38.6389°N, 120.1465°W, 2406 m, 8 July 2014, Johnson 14-159 (BRY); Butte County, ca. 0.7 miles up Humboldt Rd to Butte Meadows from Hwy 32, 40.0407°N, 121.6056°W, 1204 m, 11 June 2015, Johnson 15-045 (BRY); Calaveras County, at entrance to old lumber road off of Hwy 4 ca. 1.6 miles northeast of Camp Connell Maintenance station, 38.3356°N, 120.2278°W, 1 July 1993, Johnson 93-112 (BRY); North side of Avery-Sheep Ranch Road ca. 2 miles from Hwy 4, 38.1969°N, 120.4003°W, 1098 m, 4 June 2014, Johnson et al. 14-068 (BRY); El Dorado County, ca. 0.1 mile west of NF-8N55 on Omo Ranch Road, 38.5542°N, 120.5401°W, 1172 m, 29 May 2013, Johnson 13-189 (BRY); off road to Ice House Reservoir, 6.4 miles from jct. with Hwy 50, 38.7975°N, 120.4028°W, 1596 m, 30 May 2013, Johnson 13-219 (BRY); Sly Park Vicinity, Park Creek Road 3.7 miles from county road E16, 38.7493°N, 120.4970°W, 1207 m, 8 July 2014, Johnson 14-141 (BRY); Lassen County, west of county road A21along dirt road leading to large moist swell, 40.3601°N, 121.0039°W, 1589 m, 2 August 2006, Johnson 06-129 (BRY); Nevada County, 39.32°N, 120.75°W, 1565 m, 3 June 2014, Johnson et al. 14-018 (BRY); Placer County, Off Sawtooth Ridge Rd ca. 1.1 mile west of Dawson Spring, 39.21787°N, 120.6226°W, 1670 m, 3 June 2014, Johnson et al. 14-029 (BRY); Plumus County, south of Cascade and Lava Top, access up FS road 21N22YA, 39.6827°N, 121.1665°W, 1402 m, 10 June 2015, Johnson & Ahart 15-024 (BRY); Tehama County, two miles south of Hwy 36/89 on Hwy 32, 40.2661°N, 121.4509°W, 4590 ft, Johnson 04-140 (BRY); Shasta County, off Hwy 89 ca. 1.3 miles north of jct with Hwy A19, 41.1612°N, 121.6609°W, 1257 m, 25 June 2011, Johnson & Smith 11-058 (BRY); Trinity County, 10.3 miles north along Hastings Tie Road (FS-4N12), 40.5626°N, 123.5236°W, 1577 m, 27 June 2017, Johnson & Johnson 17-094 (BRY); Tulare County, Rabbit Meadows vicinity off Forest Service road 14S11 near 14S13A, T14S R29E S18, 2300 m, Johnson 94-065 (BRY); Tuolumne County, Twaine Harte vicinity, north side of highway 108, just west of hairpin in Lava Drive, 38.0266°N, 120.2369°W, 1159 m, 5 June 2014, Johnson et al. 14-077 (BRY); east of the Punch Bowl, north side of 4N12 ca. 5.4 miles east-northeast from junction with highway 108, 38.2386°N, 119.9496°W, 2178 m, 5 June 2014, Johnson et al. 14-108 (BRY); Idaho: Blaine County, two miles above Alturas Lake, above Alpine Creek, 7400 ft, 23 June 1941, Cronquist 2661 (IDS); Boise County, at the 62 mile marker of Highway 21, ca. 8 miles south of Lowman, 44.02°N, 115.62°W, 1859 m, 14 July 2003, Porter & Machen 13772 (BRY); Idaho County, Trail to Lake Serene, 45.1961°N 116.1907°W, 2169 m, 12 July 2013, Smith et al. 11162 (BRY, SRP scan); Valley County, FR 626, west of Sagehen Reservoir, Sagehen Basin, 44.3196°N, 116.1547°W, 1845 m, 17 July 2011, Smith 9922 (BRY, SRP scan); Brundage Mt., 7000 ft, 23 July 1940, Davis 2930 (IDS); Nevada: Douglas County, Carson Range, Genoa Peak Road, 2560 meters, 13 August 1974, Williams 74-D-83 (RENO scan); Nevada, Washoe County, Carson Range, Little Valley, near bridge, 1981 meters, 22 June 1974, Tiehm s.n. (RENO scan); Oregon: Crook County, Little Hay Creek vicinity, along Forest Service Road 150 0.1 miles north of jct with forest service road 2610, T13S R19E S22, Johnson 97-133 (BRY); Harney County, Steens Mountain Loop Byway, 1 km below jct with Kiger Gorge turnoff, 42.69°N, 118.59°W, 8251 ft, 21 July 2007, Johanson 07-76 (WTU scan); Jackson County, Just north of Hwy 66 along Moon Prairie Rd, 42.1263°N, 122.3321°W, 1161 m, 29 June 2017, Johnson & Johnson 17-147 (BRY); Josephine County, Upper Biglow Lake, 10 July 1949, Baker & Ruhle 385 (IDS scan, WTU scan); Washington: Asotin County, Anatone Butte vicinity ca. 7.2 miles west of highway 129 on West Mountain Road, 1400 m, 2 July 1994, Johnson & Johnson 94-049 (BRY); ca. 0.5 mile west of Anatone Butte, 10 miles southwest of Anatone, T7N R45E, S2, 4700 ft, 12 June 1949, Cronquist 5847 (ID scan, WTU scan WS); Chelan County, Rainbow Creek drainage, ca. 4.5 miles north of Stehekin River, 3000 ft, 19 June 1971, Naas & Naas 851 (WWB scan); Columbia County, Godman Spring campground, 18.5 miles southwest of Dayton, 46.10°N, 117.7861°W, 1753 m, 12 July 2004, Legler 2014 (WTU scan); Klickitat County, dry hills, Falcon Valley, 18 July 1908, Suksdorf 168 (WTU ×3 scan).

By elevating Navarretia divaricata subsp. vividior to species status, as done below, N. divaricata subsp. divaricata henceforth is designated simply N. divaricata. Fresh N. divaricata have no noticeable odor. The reported presence of this species in Montana is based on a single, misidentified specimen collected in an agricultural field; that specimen differs from N. divaricata in branching structure, having pinnately divided leaves, and possessing different bract and calyx morphology (our determination is N. squarrosa (Eschsch.) Hook. & Arn. [MONT-68910 scan!]. Though the protologue provides no mention of N. divaricata, Peck’s rationale for recognizing N. prolifera var. breviflora as distinct from N. divaricata can be inferred from the key and species descriptions in the first edition of his Manual of the Higher Plants of Oregon (Peck 1941). Examination of the type reveals it is simply a narrow, more erect N. divaricata that fits well within the range of variation observed in this species. Peck, perhaps influenced by Mason (1951), came to realize this and removed N. prolifera var. breviflora from the second edition of his manual (Peck 1961).

Navarretia divaricata differs from the remaining divaricately branched taxa of Navarretia (i.e., those treated below plus N. crystallina L.A. Johnson & D.Gowen, N. miwukensis D.Gowen & L.A.Johnson, and N. prolifera, in having two of its three stigmatic lobes nearly entirely fused, and in having unequal fruit valves with two of the three valves normal sized and bearing a septum, while the third valve is smaller and lacks a septum entirely or nearly so (Cronquist et al. 1984; personal observation). These other species have three lobed stigmas and three equal valves, each bearing a septum. Navarretia divaricata’s flowers, ± 4 mm long, are among the smallest in Navarretia and typically dry with pink lobes with a white or yellowish throat and tube, though the throat and tube may at times be streaked with red. On herbarium specimens, the contrast between darker, pink lobes and light, whitish or yellowish tube is preserved on many flowers even on specimens 150 years old (Fig. 1). This coloration pattern enables this species to be determined without dissecting flowers to observe the stigma or fruit valves.

Figure 1. 

Navarretia divaricata. A Pressed specimen showing plant habit, scale bar = 1 cm (Johnson 14-143) B Flowering head in the field, scale bar = 2 mm (Johnson 15-045) C–E Equivalent magnification, scale bar = 2mm C Pressed flowering head showing typical coloration of dried flowers (Johnson 16-024) D Dried fruit, showing dehiscence from base upward typical in all of the species detailed herein (Johnson 16-024) E Fresh flowering head dissected with corolla removed to show style and two-lobed stigma (with third lobe nearly entirely fused to one of the two apparent lobes; Johnson 16-024) F, G Fresh flowers showing typical coloration (Johnson 15-045), equivalent magnification, scale bar = 2 mm. All photographs by L. A. Johnson and vouchers deposited at BRY.

Figure 2. 

Distribution of Navarretia divaricata (black squares) occurrences across its native range in the western United States.

Based on Navarretia divaricata var. vividior Jeps. & V.L.Bailey.

Taprooted annual herbs to 12(–15) cm tall and 20(–25) cm wide, sometimes larger, often wider than tall. Primary stem erect, terminating in an inflorescence head 1–2(–4) cm above the cotyledons; generally greatly exceeded by secondary stems, with tertiary, and quaternary stems present on larger plants; higher order branches arise from axils of proximal inflorescence bracts, axils of leaves subtending the primary head, or less commonly, leaves within 1 cm of an inflorescence head; branches ascending to spreading and ± leafless, except for leaves subtending higher order branches or within 1 cm of a head; stem and branches reddish-brown, commonly glandular-villous, the trichomes generally greater than 0.5 mm (often ± 1mm) long, sometimes glabrescent; distal-most branches generally 0.3–0.5 mm in diameter. Cotyledons two, linear, entire, united at base. Leaves somewhat glandular-pubescent proximally, less so distally; leaves at the lowermost nodes opposite, linear-filiform, and widened at the point of stem attachment, the proximal nodes often congested with overlapping leaf bases. More distal leaves alternate, entire, or more commonly with 1–3(–5) paired or unpaired linear lateral lobes 1–10 mm long attached along the proximal 3–5(–15) mm of the leaf, with an elongated, linear terminal segment. Inflorescences head-like, largest generally ≥ 12 mm diameter (exclusive of bract tips; ≥ 18 mm with bract tips), mostly 10–25-flowered, glandular-pubescent with some minutely-glandular villous trichomes proximally. Inflorescence bracts < 15(–20) mm long, palmatifid to subpalmatifid; outermost 1–2 bracts with a short achlorophyllous base and 2–3(–4) pairs of lateral lobes flanking an elongate terminal lobe, the distal pair of lateral lobes sometimes shorter and reflexed somewhat out of plane relative to the other lobes; bract bases become larger and clasping centripetally with lateral lobes reduced to a single pair departing from near the apex of the bract base flanking the central terminal lobe, all bract lobes chlorophyllous, entire, long tapering acute. Bracts somewhat minutely-glandular villous abaxially, often more densely villous adaxially and proximally along the lobes just above the bract base, glands becoming more prominent and their stipe diminishing in length toward the bract tips. Flowers actinomorphic, calyces mostly 4–7.5(–8.5) mm long, tube ~ 1.5–2.5 mm; costae entire, long tapering acute, strongly unequal to subequal with typically two costae longer than the other three; costae narrowing proximally, the shorter ones narrower at base than the intercostal membrane and the longer ones subequal with the membrane; calyx tube achlorophyllous, glandular-puberulent on the intercostal membrane with the costae at least somewhat glandular-villous, the gland stipes longest along the costae at the junction with the intercostal membrane, diminishing in length toward the chlorophyllous costae tips (may be glabrescent with age); intercostal membrane v-shaped at sinus. Corolla generally equal or shorter than longest calyx costae at anthesis but exceeding the calyx as fruit matures, narrowly funnelform, glabrous, 5.0–7.2 mm long, lobes 0.8–1.1(–1.4) mm long × 0.6–0.9(–1.2) mm wide, tube white proximally, distal tube white or yellow, throat bluish, sometimes streaked with magenta, lobes medium bluish-lavender; tube base expanding and investing the fruit apex. Stamen filaments unequal, 0.3–1.2 mm long, inserted unequally 0.3–1.3 mm below corolla sinuses, anthers ± included in throat to exserted less than half the length of the corolla lobes; pollen blue (white rarely?), apertures pantoporate, acolpate; sexine seimitectate, reticulate, heterobrochate. Ovary three-chambered, stigmatic lobes three, included in to slightly exserted from corolla throat; capsule ~ 2.3–3.3 mm long, dehiscing circumcisally around the base with valves splitting upward. Seeds generally 5–7(8) per locule, medium brown, ovoid-angular, mucilaginous when wet. Nuclear gene loci showing allotetraploid PCR amplification patterns.

Navarretia vividior occurs in soils influenced by volcanic activity with favorable water status such as the edges of ephemeral pools and transient rivulets, to open flats or gentle slopes in forested areas from 300–1600 meters elevation. It occurs predominately in the North Coast Range from Lake and Sonoma Counties, California in the south to Humboldt, Trinity, and the western edge of Shasta County in the north (Fig. 4). A few populations cross the central valley and occur on the western flank of the northern Sierra Nevada/southern Cascade Range in Butte County, California, where they flower in late May–early June, rather than late June–July as is typical for species in the North Coast Range.

As defined here, Navarretia vividior is distributed more narrowly than previously considered. Some historical populations have not been revisited for ±100 years, though other known occurrences have been revisited multiple times over the past 20 years with no apparent change in local numbers (beyond what may be expected during drought years). Following IUCN (2012) Red List version 3.1 criteria, this species is most accurately characterized as data deficient, though it likely borders between being Vulnerable to a species of Least Concern.

This specific epithet is derived from the Latin vividus, lively or vigorous, with the comparative ending -ior, more so, in reference to the larger, more robust habit and flowering heads this taxon possesses in comparison to N. divaricata. Alternative epithets of var. vividia and var. fertilior were considered by Jepson and Bailey for this entity, as indicated by annotations on the type sheet.

UNITED STATES OF AMERICA. California: Butte County, North of Magalia at Old Coutelenc Site, along Coutelenc Rd, 1.7 miles south of junction with Skyway at Lovelock, 17 June 1980, Schlising & Banchero 3739 (CHSC); Upper Bidwell Park, Chico, on the north rim overlooking Sycamore Creek Canyon about 1.8 miles east of the power lines, 1280 ft, 30 May 1983, Oswald 578 (CHSC); South of Cohasset off of Cohasset Highway, T23N R2W S8, 4 June 1979, Schlising 3435 (CHSC); Colusa County, Along Pacific Ridge Road (16N06) 0.5 miles east of road to Spanish Ridge and Hough Springs, 39.2236°N, 122.625°W, 3450 ft, 3 July 1998, Janeway & Isle 5711 (CHSC); Humboldt County, Waif on river bar, valley of Van Duzen River opposite Buck Mtn, 1000 ft, 27 June–30 July 1908, Tracy 2721 (UC); Little Van Duzen River, 23 June 1937, Eastwood & Howell 4813 (CAS); Lake County, Mt. St. Helena, 6 June 1915, Eastwood 4706; Bartlett Springs, 9 June 1938, Jepson 18938 (JEPS); Boggs Lake, at base on Mount Hanna, 29 June 1945, Mason 12629 (DS); Margin of Boggs Lake, 3000 ft, 29 June 1945, Baker 11088 (CAS); 3.5 miles by road east of Seigler Springs, margin of Snow’s Lake, 2150 ft, 26 June 1956, Crampton 3646(AHUC); About 1/4 mile down Harrington Flat Road from Bottle Rock Rd, where access road follows under powerlines, 2850 ft, 7 June 1981, Knight & Knight 4148 (CAS); Bogg’s Lake Vicinity, between Harrington Flat Road and the Bogg’s Lake parking area, to the north side of road along the power line corridor, 38.8904°N, 122.7837°W, 862 m, 13 May 2004, Johnson 04-032 (BRY), and 12 July 2016, Johnson 16-029 (BRY); Bartlett Mountain Ranger Station, 24 Sept 1949, Crampton 494B (AHUC, DAV); About 6.3 miles from Hwy 20 along Bartlett Spring Road, at junction with Pinnacle Rock Road, 39.1345°N, 122.7769°W, 3915 ft, 10 May 2005, Johnson 05-021 (BRY) and 12 July 2016, Johnson 16-032 (BRY); Mendocino County, Chamise Mt. north of Bell Springs, 3500 ft, 9 July 1934, Tracy 13326 (UC); Jeep trail above Bell Springs Rd 11 miles south of jct with Harris Rd, 39.9667°N, 123.6113°W, 1092 m, 28 June 2017, Johnson & Johnson 17-119 (BRY); Eden Valley Ranch, vernal pool area, north of Hearst, 1249.6 m, 11 July 1978, Wheeler 506 (CAS); Napa County, Gravelly slope in chaparral, edge of the Crater Country, 13 July 1930, Howell 5347 (CAS); Robert Louis Stevenson State Park; along trail to Table Rock on East side of Hwy from parking area off Hwy 29, 38.6513°N, 122.5867°W, 802 m, 30 May 2009, Johnson & Gowen 09-049 (BRY); Shasta County, Harrison Gulch Rd, 2.4 miles north of Hwy 36 west of Platina, T29N R10W S3, 3100 ft, 1 July 1996, Oswald, Ahart & Ondricek-Fallsheer 7906 (CHSC) and 13 July 2016, Johnson 16-062 (BRY); 0.3 miles north of Hwy 36 along NF-29, 40.3699°N, 122.9380°W, 893 m, 27 June 2017, Johnson & Johnson 17-052 (BRY); Sonoma County, Mayacmas Mtns, Caldwell Pines, ca. 3.5 miles west of Glenbrook and Bottle Rock Rd, 38.841°N, 122.815°W, 2350–3000 ft, 27 June 1975, Neilson & Sholars 3294b (DAV); Tehama County, West of Red Bluff and south of Platina on Forest Route 45 (Tedoc Mtn. Rd), 6.3 miles south of Hwy 36, 3800 ft, 12 July 1995, Oswald & Ahart 7022 (CHSC) and 13 July 2016, Johnson 16-058 (BRY); Trinity County, Along Wildwood Rd north of Hwy 36 between mile post 7 and 8, where drainage crosses and goes under road, 24 June 2005, Gowen 452 (BRY, JEPS) and 13 July 2016, Johnson 16-063b (BRY); 6.2 miles north of Hwy 36 along Hastings Tie Road, 40.5092°N, 123.5041°W, 1597 m, 27 June 2017, Johnson & Johnson 17-082 (BRY).

Navarretia vividior are mephic when fresh. Crampton 494B [AHUC-38375] (collected by McMillan at the Bartlett Mountain Ranger Station) is a voucher for a tetraploid chromosome count from pollen mother cells. Our low copy nuclear gene data indicate this species is an allotetraploid, with N. modocensis the paternal diploid parent and N. aeroides the maternal diploid parent. Four of the eight paratypes listed for N. divaricata var. vividior belong here: Chestnut & Drew s.n. [UC-52826], Tracy 2721 [UC-133661], Tracy 13326 [JEPS-70300], and Jepson 18938 [JEPS-70299]; a fifth paratype, Condit s.n. [UC-455660], is difficult to place with confidence; it was collected from ‘garden soil’ and thus its original source is uncertain, but its smaller corolla features suggest N. vividior. The Torrey 302 syntype of Gilia divaricata Torr. ex Gray also belongs here.

Navarretia vividior is readily distinguished from N. divaricata with its larger flowering head, larger flowers, equally divided 3-lobed stigma, typically blue pollen, and bluish-lavender corolla lobes and throat (Fig. 3). Stems are typically larger in diameter and invested with long, gland tipped hairs. The evenly 3-lobed stigmas, larger flowers, and some variation in flower color with colored lobes, throat, or both apply to three additional species that have heretofore generally fallen under the umbrella of N. divaricata subsp. vividior. These species are described and differentiated below.

Figure 3. 

Navarretia vividior. A Pressed specimen showing plant habit, scale bar = 1 cm (Johnson 16-066) B Flowering head in the field, scale bar = 2 mm (Johnson 16-063b) C–F Equivalent magnification, scale bar = 2mm C, D Pressed flowering head showing typical coloration of dried flowers and blue pollen (Johnson 16-029, 16-063b, respectively) E, F Fresh flowers showing typical coloration (Johnson 16-063b). All photographs by L. A. Johnson and vouchers deposited at BRY.

Figure 4. 

Distribution of Navarretia vividior (circles), N. modocensis (squares), N. aeroides (triangles), and N. torreyella (4-pointed stars) occurrences across their native range in California and southern Oregon, United States. Instances of observed syntopy are indicated with the hexagon and pentagon, as defined in the legend.

United States of America. California: Shasta County, west side of Hwy 89, ca 10 miles north of junction with Hwy 299. Meadow area adjacent to railroad tracks, 41.0450°N, 121.6326°W, 2992 ft, 17 June 2004, L.A. Johnson 04-130 (holotype BRY! [BRY-614952]; isotypes JEPS! RSA! and to be distributed).

A species similar to Navarretia vividior, but distinguished by being diploid, rather than allotetraploid, generally being more conspicuously villous in the proximal inflorescence, possessing slightly larger flowers and more exserted corollas that tend toward pinkish-lavender lobes with darker throat above a yellowish tube rather than bluish to bluish-lavender lobes with darker throat above a yellowish or whitish tube, and having white (rarely blue) rather than blue pollen.

Taprooted annual herbs to 12(–15) cm tall and 20(–25) cm wide, sometimes larger, often wider than tall. Primary stem erect, terminating in an inflorescence head 1–2(–4) cm above the cotyledons; generally greatly exceeded by secondary stems, with tertiary, and quaternary stems present on larger plants; higher order branches arise from axils of proximal inflorescence bracts, axils of leaves subtending the primary head, or less commonly, leaves within 1 cm of an inflorescence head; branches ascending to spreading and ± leafless, except for leaves subtending higher order branches or within 1 cm of a head; stem and branches reddish-brown, commonly glandular-villous, the trichomes generally greater than 0.5 mm (often ± 1mm) long, sometimes glabrescent; distal-most branches generally 0.3–0.5 mm in diameter. Cotyledons two, linear, entire, united at base. Leaves somewhat glandular-pubescent proximally, less so distally; leaves at the lowermost nodes opposite, linear-filiform, and widened at the point of stem attachment, the proximal nodes often congested with overlapping leaf bases. More distal leaves alternate, entire, or more commonly with 1–3(–5) paired or unpaired linear lateral lobes 1–10 mm long attached along the proximal 3–5(–15) mm of the leaf, with an elongated, linear terminal segment. Inflorescences head-like, largest generally ≥ 12 mm diameter (exclusive of bract tips; ≥ 18 mm with bract tips), mostly 12–20-flowered, sometimes more, glandular-pubescent, generally with conspicuous, minutely-glandular villous trichomes proximally. Inflorescence bracts < 15(–20) mm long, ± palmatifid to subpalmatifid; outermost 1–2 bracts with a short achlorophyllous base and 2–3 pairs of lateral lobes flanking an elongate terminal lobe, the distal pair of lateral lobes sometimes shorter and reflexed somewhat out of plane relative to the other lobes; bract bases become larger and clasping centripetally with lateral lobes reduced to a single pair departing from near the apex of the bract base flanking the central terminal lobe, all bract lobes chlorophyllous, entire, long tapering acute. Bracts minutely-glandular villous abaxially, often more densely villous adaxially and proximally along the lobes just above the bract base, glands becoming more prominent and their stipe diminishing in length toward the bract tips. Flowers actinomorphic, calyces mostly 5–7.5(–12) mm long, tube ~ (1.5–)2–2.5(–3) mm; costae entire, long tapering acute, strongly unequal to subequal with typically two costae longer than the other three; costae narrowing proximally, the shorter ones narrower at base than the intercostal membrane and the longer ones subequal with the membrane; calyx tube achlorophyllous, glandular-puberulent on the intercostal membrane with the costae at least somewhat glandular-villous, the gland stipes longest along the costae at the junction with the intercostal membrane, diminishing in length toward the chlorophyllous costae tips (may be glabrescent with age); intercostal membrane v-shaped at sinus. Corolla generally equal to exceeding the calyx costae at anthesis and exceeding the calyx further as fruit matures, narrowly funnelform, glabrous, 6.0–8.2 mm long, lobes (1.0–)1.2–1.5(–1.95) mm long × 0.8–1.4 mm wide, tube white proximally, yellow distally, throat lavender–purple or purplish streaked, lobes light to dark pinkish-lavender; tube base expanding and investing the fruit apex. Stamen filaments unequal, 0.3–1.3 mm long, inserted unequally 0.3–1.6 mm below corolla sinuses, anthers ± included in throat to exserted less than half the length of the corolla lobes; pollen white (uncommonly blue), apertures pantoporate, acolpate; sexine seimitectate, reticulate, heterobrochate. Ovary three-chambered, stigmatic lobes three, included in to slightly exserted from corolla throat; capsule ~ 2.6–3.8 mm long, dehiscing circumcisally around the base with valves splitting upward. Seeds generally 4–9 per locule, medium brown, ovoid-angular, mucilaginous when wet. Nuclear gene loci showing diploid PCR amplification patterns.

Figure 5. 

Navarretia modocensis. A Pressed specimen showing plant habit, scale bar = 1 cm (Johnson 04-130) B Flowering head in the field, scale bar = 2 mm (Johnson 16-072) C, D Pressed flowering heads showing range of typical coloration, equivalent magnification, scale bar = 2 mm (Johnson 04-124, 04-130, respectively) E–G Fresh flowers showing typical coloration and white pollen, equivalent magnification, scale bar = 2 mm. (E, F = Johnson 14-170; G = Johnson 16-072). All photographs by L. A. Johnson and vouchers deposited at BRY.

Navarretia modocensis occurs in volcanic influenced soils in forest openings and sagebrush slopes from (390–)800–1700 meters predominately in the Modoc Plateau of northeastern California and adjacent southern Oregon, but extending south to the western flank of the northern Sierra Nevada/southern Cascade Range in Butte County, California, and with a long-distance disjunct occurrence in San Benito County, California. Flowering occurs primarily in (April–)June–July.

Navarretia modocensis has many occurrences throughout its range and is often abundant when encountered. It is a species of Least Concern following IUCN (2012) Red List version 3.1 criteria.

From the Latin -ensis, origin or place, combined with Modoc, in reference to the Modoc Plateau on which this taxon predominantly (but not exclusively) occurs.

(paratypes). UNITED STATES OF AMERICA. California: Butte County, North east of Forest Ranch, 2.3 miles east and southeast of Hwy 32 along Garland Road, T24N R3E S33, 2960 ft, 13 June 1980, Schlising & Azevedo 3699 (CHSC) and 20 May 2017, Johnson 17-027 (BRY); Top of North Table Mt, ca 200 meters north of junction of Cherokee Rd and east edge of Mt, T20N R4E S17 NE1/4, 18 May 1979, Jokerst, Devine, & Greenstein 0462 (CHSC); Ponderosa way on Musty Buck Ridge between Cohasset and Big Chico Creek, T24N R2E S25 SE NW 1/4, 2500 ft, 16 May 1989, Oswald 3773 (CHSC); About 0.5 mile east of Kunkle Creek, about 2.5 miles south-east of Paradise, 1500 ft, 29 May 1979, Ahart 1906 (CHSC); Lassen County, Off Hwy 139, up slope and across fence at a pull out area on west side of road, near mile marker 49.5, 40.9833°N, 120.7950°W, 1615 m, 9 July 2014, Johnson 14-176 (BRY); Murrer Meadow Rd, ca 3 miles east of Eagle Lake Biological Station, 5100 ft, 24 June 1967, Stern 2418 (CHSC); 100 yards south of Hwy 44, 34 miles northwest of Susanville, 26 June 1974, Stern 5863 (CHSC); Ash Valley RNA/ACEC, T37N R11E S5, 5100 ft, 29 June 1993, Schoolcraft 2303 (CAS; mixed collection with N. divaricata); Near Bar Springs road, just off Hwy 299 near top of grade, ca. 7.4 miles east of county line, 41.0669°N, 121.2315°W, 1383 m, 14 July 2016, Johnson 16-075 (BRY); Modoc County, Vicinity of mile maker 9.37 off of Hwy 299, near Roney Flat and Johnson Creek Roads, 41.30602°N, 120.89584°W, 1428 m, 25 June 2011, Johnson & Smith 11-064 (BRY); Fandango Pass vicinity, helicopter pad 5.1 miles from Hwy 395 on Fandango Pass Road (Rd 9) at south end of Buck Creek Fire station and intersection with Jack’s Rd, 41.8639°N, 120.2849°W, 1586 m, 9 July 2014, Johnson 14-170 (BRY); About 0.3 miles up 41N25 (Shake Canyon) off of Hwy 139/299, 41.3825°N, 120.9437°W, 1415 m, 9 July 2014, Johnson 14-173 (BRY); 0.6 miles along Johnson Creek road from jct with Hwy 299/139 about 9.5 miles north of county line, 41.3120°N, 120.8874°W, 1479 m, 14 July 2016, Johnson 16-083 (BRY); 0.7 miles east of Hwy 139 along road FS 46, 41.5090°N, 120.9750°W, 1519 m, 14 July 2016, Johnson 16-086 (BRY); Little Hot Spring Valley, 15 June 1894, Baker s.n. (UC 23519); San Benito County, Condon Peak vicinity, 36.3205°N, 120.63817°W, 4683 ft, 5 June 2016, O’Dell s.n. (BRY; JEPS); Shasta County, Fuller Flat. north side of Hwy 299, just west of mile marker 64.71, about 14 miles west of junction with Hwy 89, 40.86532°N, 121.8238°W, 3792 ft, 17 June 2004, Johnson 04-124 (BRY, JEPS, RSA) and 14 July 2016, Johnson 16-072 (BRY); Meadow 0.3 miles past Rock Creek, south side of road 37, 41.0245°N, 121.7164°W, 3180 ft, 17 June 2004, Johnson 04-137 (BRY); Rock Creek vicinity; north of Summit Lake Road (Forest Route 38N10) ca. 3.5 miles from junction with Clark Creek Road, east of Lake Britton & Hwy 89, 41.0218°N, 121.7217°W, 973 m, 17 June 2005, Johnson & Zhang 05-157 (BRY); 0.4 miles south of Hwy 299 along Cassel road, 40.9561°N, 121.5772°W, 926 m, 14 July 2016, Johnson 16-073; Ahjumawi Lava Springs State Park, 3 miles north of McArthur, along Spatter Cone Trail, 3450 ft, 24 May 2004, Fischer & Marr 0213 (CHSC); Fall River Springs, 3500 ft, June 1903, Hall & Babcock 4213 (UC); Montgomery Creek, 27 June 1912, Eastwood 631 (CAS); Willow Creek Ranch about 6.8 miles south of the intersection of California State Rd 89 and Squaw Valley Rd in McCloud, 2900 ft, 29 May 1995, Almeda & Eisenhardt 7417 (CAS); Tehama County, High Cascade Range. Along Road 27N08 to Deer Creek and Onion Butte, ca. 4.6 miles from jct with Hwy 32 at sharp hairpin bend (ca. 0.9 miles from Deer Creek), 40.1624°N, 121.5999°W, 994 m, 11 June 2015, Johnson 15-047 (BRY); North side of Hwy 36 in ecotone gradation between mixed conifer forest and chaparral at mile marker 75.49, about 12.8 miles west of jct with Hwy 89 to Mt. Lassen, 40.34734°N, 121.7299°W, 1138 m, 12 June 2015, Johnson 15-057 (BRY); Along Ponderosa Way at crossing of Soap Creek; , 40.3933°N, 121.8033°W, 2450 ft, 30 May 1997, Taylor 16013 (BRY, JEPS); North side of Ishi Wilderness at Rancheria Creek Trailhead, 40.2052°N, 121.6141°W, 3210 ft, 31 May 2003, Hillaire & Elliott 327 (CHSC); 33 meters above Road 27N08, 2.3 km east of major hairpin turn, 40.1586°N, 121.6019°W, 1000 m, 30 May 2004, Janeway & Castro 8123 (CHSC); North facing slope along Powerline Road just southwest of north fork of Little Antelope Creek, 40.1833°N, 121.9186°W, 1890 ft, 25 April 2009, Castro & Janeway 1778 (CHSC); Oregon: Jackson County, Near trail, 19 June 1931, Howell 6766 (CAS); 7 miles southwest of Prospect, 2100 ft, 28 June 1939, Hitchcock and Martin 4992 (IDS; OSC); On Copco Rd., about 1/2 mile south of Ranch, just north of California line, T41S R4E S10 SW1/4, 18 June 1990, Rolle 237 (OSC); Klamath County, 11 miles east of Blye, 30 June 1937, Peck 19655 (WILLU); Hwy 140, about 4.7 miles west of Lake County line, to south of highway near old dirt road, 12 July 1995, Johnson 95-053 (BRY); Lake County, 24 miles northwest of Lakeview, 25 June 1927, Peck 15226(WILLU); jct of FS-3870 and highway 140, 42.2632°N, 120.7197°W, 1529 m, 29 June 2017, Johnson & Johnson 17-159 (BRY).

Navarretia modocensis are mephic when fresh. Three of the nine paratypes listed for N. divaricata var. vividior belong here: Baker s.n. [UC-23519], Hall & Babcock 4213 [UC-127856], and Austin 827 [UC-133706]. A collection from Yosemite National Park, Mason 12480a [UC-908393], likely belongs here also, representing a second disjunct population for this species. Pollen is usually white in N. modocensis, but blue pollen has been observed.

Navarretia modocensis is the species most likely to be visually confused with N. vividior. Though N. modocensis can have larger inflorescence heads, calyces, and flowers than N. vividior, the range of measurements in these features overlap. We are fairly confident (on fresh flowers) that N. modocensis has a yellow corolla tube on fresh flowers, and that populations with blue pollen are uncommon, but we are less certain that N. vividior always has yellow on its tube, or that populations with white pollen do not exist (given white results from the absence of pigment; we have collected species in several genera, including Navarretia that are characterized by blue pollen but occasionally have populations with white pollen). The more robust features of N. modocensis contrast more sharply with N. aeroides, which has smaller flowers, smaller inflorescence heads, thinner branches, and is visually much more glandular and less villous in its inflorescence heads. The smaller dimensions and very different corolla coloration patterns also readily distinguish N. divaricata and N. torreyella from N. modocensis.

United States of America. California: Calaveras County, west of Avery, at the end of a short forest service road off of Avery Sheep Ranch Road, 38.19488°N, 120.39969°W, 3695 ft,17 June 2015, D. Gowen, 1303 (holotype BRY! [BRY-627257]; isotypes JEPS! RSA!).

A species similar to Navarretia vividior, but distinguished by being diploid, rather than allotetraploid, and being less robust in all respects; N. aeroides has smaller inflorescence heads that are conspicuously stipitate-glandular throughout (sometimes inconspicuously villous proximally), thinner branches, tends toward smaller corollas, and has stem trichomes mostly 0.5mm or less rather than mostly ± 1 mm.

Taprooted annual herbs to 9(–12) cm tall and 15(–22) cm wide, sometimes larger, often wider than tall. Primary stem erect, terminating in an inflorescence head 1–2(–4) cm above the cotyledons; generally greatly exceeded by secondary stems, with tertiary, and quaternary stems present on larger plants; higher order branches arise from axils of proximal inflorescence bracts, axils of leaves subtending the primary head, or less commonly, leaves within 1 cm of an inflorescence head; branches ascending to spreading and ± leafless, except for leaves subtending higher order branches or within 1 cm of a head; stem and branches reddish-brown, glandular-pubescent or sparingly so, the trichomes mostly less than 0.5 mm long; distal-most branches filiform, generally no more than 0.3 mm in diameter. Cotyledons two, linear, entire, united at base. Leaves somewhat finely stipitate-glandular proximally, less so distally; leaves at the lowermost nodes opposite, linear-filiform, and widened at the point of stem attachment, the proximal nodes often congested with overlapping leaf bases. More distal leaves alternate, entire, or more commonly with 1–3(–5) paired or unpaired linear lateral lobes 1–8 mm long attached along the proximal 3–5(–15) mm of the leaf, with an elongated, linear terminal segment. Inflorescences head-like, generally ≤ 10 mm diameter (exclusive of bract tips; ~15 mm with bract tips), mostly less than 10-flowered, sometimes more, ± conspicuously glandular. Inflorescence bracts < 10(–12) mm long, ± palmatifid to subpalmatifid; outermost 1–2 bracts with a short achlorophyllous base and 2–3 pairs of lateral lobes flanking an elongate terminal lobe, the distal pair of lateral lobes sometimes shorter and reflexed somewhat out of plane relative to the other lobes; bract bases become larger and clasping centripetally with lateral lobes reduced to a single pair departing from near the apex of the bract base flanking the central terminal lobe, all bract lobes chlorophyllous, entire, long tapering acute. Bracts sparsely glandular-villous abaxially, more densely glandular-villous adaxially and proximally along the lobes just above the rachis, with the stipe of each gland diminishing in length toward the bract tips. Flowers actinomorphic, calyces mostly 4.0–6.0(–8.5) mm long, tube ~ 1.3–2.2–(2.5) mm; costae entire, long tapering acute, strongly unequal to subequal with typically two costae longer than the other three; costae narrowing proximally, the shorter ones narrower at base than the intercostal membrane and the longer ones subequal with the membrane; calyx tube achlorophyllous, glandular-puberulent on the intercostal membrane and proximal costae, gland stipes lengthen on the costae at the junction with the intercostal membrane, diminishing in length toward the chlorophyllous costae tips; intercostal membrane v-shaped at sinus. Corolla generally ± equal to the calyx costae at anthesis but exceeding the calyx as fruit matures, narrowly funnelform, glabrous, 4.2–6.0 mm long, lobes 0.75–1.3 mm long × 0.5–0.9(–1.0) mm wide, tube white, transitioning to a bluish throat and lobes in some populations (drying bluish purple, with the distal tube showing hints of magenta or somewhat brownish) or remaining white in others (drying with white or light blue lobes and throat with brownish or magenta distal tube); tube base expanding and investing the fruit apex. Stamen filaments unequal, 0.2–0.55 mm long, inserted unequally 0.4–0.9 mm below corolla sinuses, anthers included in throat to slightly exserted; pollen blue or white, generally matching corolla lobe coloration, apertures pantoporate, acolpate; sexine seimitectate, reticulate, heterobrochate. Ovary three-chambered, stigmatic lobes three, included in to slightly exserted from corolla throat; capsule ~ 2.4–3.4 mm long, dehiscing circumcisally around the base with valves splitting upward. Seeds generally 4–8 per locule, medium brown, ovoid-angular, mucilaginous when wet. Nuclear gene loci showing diploid PCR amplification patterns.

Figure 6. 

Navarretia aeroides. A Pressed specimen showing plant habit, scale bar = 1 cm (Gowen 1303) B Flowering head in the field, scale bar = 2 mm (Johnson 14-142) C–F Equivalent magnification, scale bar = 2mm C, D Pressed flowering head showing range of coloration in dried flowers (Johnson 16-070, Gowen 1303, respectively) E, F Fresh flowers showing range of coloration (Johnson 16-063a, Johnson 15-065, respectively). All photographs by L. A. Johnson and vouchers deposited at BRY.

Navarretia aeroides prefers (reddish) clay soils in forest openings from 400–1350(–1900) meters elevation. Occurrences are widely scattered in the Sierra Nevada from Mariposa County, California in the south to Plumas County in the North, and in the Trinity mountains of the North Coast Range, California. This species flowers primarily June–July.

Many historical collections of this species are sufficiently general in their locality descriptions in areas now populated that our efforts to relocate them, compounded by recent drought years, have been unsuccessful. On the other hand, all but two of our collections were made serendipitously, in the course of looking for other species, suggesting our present knowledge of occurrences is incomplete. Following IUCN (2012) Red List version 3.1 criteria, this species is most accurately characterized as data deficient, though it may be Vulnerable based on the fragmented nature of a limited number of occurrences.

From the Latin aeroides, like the sky or sky-blue, in reference to the typical color of the corolla.

(paratypes). UNITED STATES OF AMERICA. California: El Dorado County, Lake Valley, July 1908, Brandegee s.n. (UC; mixed collection with N. divaricata); 3 miles east of Camino at C.C.C. Camp Snowline, 3400 ft, 6 July 1943, Robbins 1247 (JEPS, UC); 0.1 mi north of Rescue, along deer valley road, 1300 ft, 30 June 1945, Robbins 2015 (UC); 3 miles southeast of Greenwood, Coloma Canyon, 18 June 1957, Crampton 4233 (AHUC); 6.4 miles east of Diamond Springs, 6 June 1960, Crampton 5546 (AHUC); Sly Park Vicinity. Park Creek Road off of county road E16, 38.7493°N, 120.4970°W, 1207 m, 8 July 2014, Johnson 14-142 (BRY, JEPS); Mariposa County, Telegraph Hill Road, ca. 7 miles from Hwy 140 via E. Whitelock Road, 37.5773°N, 120.0038°W, 809 m, 9 June 2015, Johnson 15-005 (BRY, JEPS); Nevada County, Colfax, 3 July 1882, Jones 3417. (POM, scan); Colfax, 20–22 Jun 1912, Eastwood 498 (CAS, UC); Rattlesnake Creek, 5 miles south of Grass Valley, 2000 ft, 29 May 1926, Mason 3279 (UC); Bed of dried pond west of Greenhorn Creek, T16N R9E S24, 3000 ft, 27 August 1954, Raven 7980 (CAS); Placer County, Nevada City, Hospital Farm, Sierra Nevada Mtns, 5000 ft, 31 July 1915, Brainerd & Baird 236 (JEPS); 10 miles west of Forest Hill, 15 June 1955, Crampton 2921 (AHUC); Plumas County, 2.5 miles northeast of Quincy Junction on Mt Hough-Crystal Lake Road, T24N R10E S4, 4200 ft, 24 June 1981, Barbe, Fuller, & Howell 3181 (CHSC); East of Quincy, about 2.3 miles along Mt. H road from its junction with Quincy Jct Road, at intersection with 25N14, 39.9747°N, 120.8761°W, 1321 m, 12 June 2015, Johnson 15-065 (BRY, JEPS) and 14 July 2016, Johnson 16-087 (BRY, JEPS); Trinity County, Hills south above Hayfork, between Kingsbury Rd. and Bridge Gulch Rd, 25 June 2005, Gowen 462; East side of Hwy 3 south of Clair Engle Lake, ca 2.3 miles south of Tannery Gulch Road, 40.8225°N, 122.8887°W, 947 m, 16 July 2009, Johnson 09-109 (BRY); About 7.3 miles up Wildwood Rd (NF-3) from Hwy 36, 40.4514°N, 123.0649°W, 1003 m, 13 July 2016, Johnson 16-063a (BRY); South of Hayfork about 3.3 miles along Kingsbury road from jct with Morgan Hill road, 40.5074°N, 123.1469°W, 851 m, 13 July 2016, Johnson 16-070 (BRY, JEPS); Yuba County, along margin of New York Flat Road, 0.5 miles north from jct with Laporte road (possible waif), 39.4812°N, 121.2606°W, 2255 ft, 18 June 2004, Johnson 04-150 (BRY).

Navarretia aeroides are mephic when fresh. In 2015, the population first collected by Barbe, Fuller, & Howell in the mountains east of Quincy, California, was found to have been sprayed with 2,4-D (and blue indicator dye), along with N. propinqua, in an area designated for ORV use, perhaps having been mistaken for immature thistle. To date, occurrences in the Trinity Mountains can be distinguished morphologically (white corollas with magenta streaking in the throat and white pollen) from occurrences in the Sierra Nevada (blue to light blue corollas and blue pollen), yet we have resisted recognizing this difference at the subspecific level. As in any species with colored corollas, occasional white flowered individuals are observed in the Sierra Nevada among a sea of blue flowered individuals. The paratype of Gilia atrata M.E.Jones from Colfax, California [POM-75128 scan!] belongs here.

Navarretia aeroides is a smaller-featured plant than either N. vividior or N. modocensis, though its corolla overlaps in size with N. vividior. The more conspicuously glandular inflorescence heads (in side-by-side comparisons) contrasts with all of the other species detailed here, and corolla coloration, fresh and dried, readily distinguishes this taxon from N. divaricata and N. torreyella.

United States of America. California: El Dorado County, Peavine Ridge Road, along left fork (11N55) about 4.7 miles from junction with Icehouse Road, 38.7961°N, 120.4770°W, 1480 m, 26 June 2013, L.A.Johnson, R.L.Johnson, & A. Yankee 13-230 (holotype BRY! [BRY-619469]; isotypes JEPS! RSA! and to be distributed).

A species similar to Navarretia divaricata, but distinguished by having three equal stigmatic lobes and three fully developed fruit valves, and generally larger corollas with a deep maroon distal tube and throat abruptly transitioning to nearly white or less commonly pink lobes, the lobes drying lighter than the much darker throat and tube.

Taprooted annual herbs to 7(–10) cm tall and 14(–20) cm wide, sometimes larger, generally wider than tall. Primary stem erect, terminating in an inflorescence head 1–2(–3) cm above the cotyledons; generally greatly exceeded by secondary stems, with tertiary, and quaternary stems present on larger plants; higher order branches arise from axils of proximal inflorescence bracts, axils of leaves subtending the primary head, or less commonly, leaves within 1 cm of an inflorescence head; branches ascending to spreading and ± leafless, except for leaves subtending higher order branches or within 1 cm of a head; stem and branches reddish-brown, sparsely minutely glandular pubescent to glabrescent, less often villous, the trichomes generally less than 0.5 mm long; distal-most branches filiform, generally no more than 0.3 mm in diameter. Cotyledons two, linear, entire, united at base. Leaves somewhat finely stipitate-glandular proximally, less so distally; leaves at the lowermost nodes opposite, linear-filiform, and widened at the point of stem attachment, the proximal nodes often congested with overlapping leaf bases. More distal leaves alternate, entire, or more commonly with 1–3 paired or unpaired linear lateral lobes 1–5 mm long attached along the proximal 3(–15) mm of the leaf, with an elongated, linear terminal segment. Inflorescences head-like, generally ≤ 10 mm diameter (exclusive of bract tips; ~15 mm with bract tips), mostly less than 15 flowered, villous proximally, obscurely glandular. Inflorescence bracts < 10(–12) mm long, palmatifid to subpalmatifid; outermost 1–2 bracts with a short achlorophyllous base and 2–3 pairs of lateral lobes flanking an elongate terminal lobe, the distal pair of lateral lobes sometimes shorter and reflexed somewhat out of plane relative to the other lobes; bract bases become larger and clasping centripetally with lateral lobes reduced to a single pair departing from near the apex of the bract base flanking the central terminal lobe, all bract lobes chlorophyllous, entire, long tapering acute. Bracts sparsely villous abaxially, more densely villous adaxially and proximally along the lobes just above the rachis, with the distal 1/2 of each lobe more or less glabrous or with a few minute, stipitate glands. Flowers actinomorphic, calyces mostly 4.5–7.8 mm long, tube ~ 1.5–2 mm; costae entire, long tapering acute, strongly unequal to subequal with typically two costae longer than the other three; costae narrowing proximally, the shorter ones narrower at base than the intercostal membrane and the longer ones subequal with the membrane; calyx tube achlorophyllous, minutely glandular-puberulent on the intercostal membrane with the costae at least somewhat villous, the trichomes longest along the costae at the junction with the intercostal membrane, the free portion of the costae glabrous to very sparely, obscurely, and minutely glandular distally; intercostal membrane v-shaped at sinus. Corolla generally ± equal to the calyx costae at anthesis but exceeding the calyx as fruit matures, narrowly funnelform, glabrous, 4.0–6.0(–6.8) mm long, lobes 0.7–1.5 mm long × 0.5–1.0 mm wide, proximal tube white, distal tube and throat maroon, abruptly transitioning to white or whitish to uncommonly pink lobes; tube base expanding and investing the fruit apex. Stamen filaments unequal, 0.25–1.2 mm long, inserted unequally to subequally 0.2–1.2 mm below corolla sinuses, included in throat to exserted less than half the length of the corolla lobes; pollen white (uncommonly light blue), apertures pantoporate, acolpate; sexine seimitectate, reticulate, heterobrochate. Ovary three-chambered, stigmatic lobes three, included in to slightly exerted from the corolla throat; capsule ~ 2.5 mm long, dehiscing circumcisally around the base with valves splitting upward. Seeds generally 2–5 per locule, medium brown, ovoid-angular, mucilaginous when wet. Nuclear gene loci showing diploid PCR amplification patterns.

Figure 7. 

Navarretia torreyella. A Pressed specimen showing plant habit, scale bar = 1 cm (Johnson et al, 13-230) B Flowering head in the field, scale bar = 2 mm (Johnson 16-008) C–E Equivalent magnification, scale bar = 2mm. C Pressed flowering head showing coloration of dried flowers (Johnson 16-008) D, E Fresh flowers showing coloration (Johnson 13-218) F Fresh flowering head with maturing fruit, showing stretched corolla base that typically clings to fruit through maturity common in all of the species detailed herein, scale bar = 2 mm (Johnson 16-008). All photographs by L. A. Johnson and vouchers deposited at BRY.

Navarretia torreyella occurs on basalt flats, pyroclastic rubble, and clay soils from 1000–2100 meters elevation, in Butte, El Dorado, Nevada, Placer, Plumas, and Tehama Counties, California. Depending on latitude and elevation, it blooms from (May) June–July (September), beginning its flowering a little earlier than N. divaricata, and about the same as N. crystallina, when these taxa co-occur.

Navarretia torreyella has many occurrences throughout its range and is typically abundant when it is encountered. It is a species of Least Concern following IUCN (2012) Red List version 3.1 criteria.

In honor of John Torrey for the plant he recognized, before others, as distinct at the species level.

(paratypes). UNITED STATES OF AMERICA. California: Butte County, about 8 miles east of Feather Falls, 1.5 miles east of Camp 18, yellow pine forest, 1000 meters, 4 June 1982, Ahart 3533 (CAS, CHSC); About 2 road miles west of Camp Eighteen along La Porte Rd (94), then 0.2 miles north along Frey Ranch Rd, 39.6291°N, 121.1970°W, 1266 m, 10 June 2015, Johnson & Ahart 15-022 (BRY, JEPS); About 1.2 miles east of Camp Eighteen along Lumpkin Ridge Rd, 39.6277°N, 121.1473°W, 1290 m, 10 June 2015, Johnson & Ahart 15-028 (BRY, JEPS, RSA); 1.6 miles north of La Porte Road (and 1.8 miles south of south end of Sly Creek Reservoir Dam), T20N R8E S19, 23 June 1980, Schlising, Ikeda, & Banchero 3765 (CHSC); Lumpkin Ridge, T21N R7E S36, 20 May 1981, Schlising & Banchero 4059 (CHSC); Near Bull Hill Road, about 3 miles south of Butte Meadows, 1600 m, 16 August 1983, Ahart 4303 (CHSC); Jackass Flat, Mooreville Ridge, about 1 air mile northwest of the Lost Creek Reservoir Dam, 3800 ft, 20 June 1993, Ahart 6999 (CHSC); sides of a poor road, east of cow corral, about 200 yards north of the county road, about one mile west of the intersection of county road and Lumpkin Road, about 7 miles northeast of Feather Falls, 39.6294°N, 121.1983°W, 4204 ft, 2 July 2014, Ahart 19551 (CHSC); Southwest end of Lumpkin Ridge, about 6.75 air miles northeast of town of Feather Falls and 1.3 miles east of the Camp 18 site on topo maps, about 300 ft southeast of USFS Rd 22N27, 2 miles east of its junction with the county road and USFS Rd 22N94 to Fall River, T21N R7E S36 SW1/4 of SE1/4, 4250 ft, 6 June 2005, Castro 1483 (CHSC); El Dorado County, off road to Ice House Reservoir, 6.4 miles from jct. with Hwy 50, 1596 m, 38.79754°N, 120.40287°W, 30 May 2013, Johnson 13-218 (BRY, JEPS); Along Park Creek Road, 2.8 miles from junction with Mormon Emigrant Trail, 15 May 2004, Johnson 04-076 (BRY); Sly Park Vicinity, Park Creek Road off of county road E16, 38.7493°N, 120.4970°W, 1207 m, 8 July 2014, Johnson 14-143 (BRY); Nevada County, Nevada City, 20–22 June 1912, Eastwood s.n. (CAS); Indian Springs Campground, near Cisco, 26 June 1965, Day 65-146a (DAV); 1.5 miles west of Cisco Grove, on a western slope above South Fork of Yuba River, 5800 ft, 21 July 1953, Crampton 1516 (AHUC; mixed collection with Navarretia divaricata); Scotts Flat Reservoir on Deer Creek about 5 miles east of Nevada City, 3100 ft, 25 August 1965, True & J. T. Howell, 2548A (CAS); Near Grass Valley in red clay in the yellow pine and oak belt, 25 May 1919, Heller 13197 (CAS, UC); 2 miles west of Grass Valley, gravelly meadow edges, 2350 ft, 5 June 1939, Rose 39208 (CAS); hills northwest of Grass Valley, 2700 ft, 14 June 1967, Rose 67134 (BRY); Spur road off north side of Hwy 20, ca. 9–10 miles from I-80 at Yuba Pass, 1565 m, 39.3171°N, 120.7514°W, 3 June 2014, Johnson et al. 14-017 (BRY); West of meadow under power lines, about 150 yards west of paved road, southwest of Lake Spaulding, 39.3174°N, 120.6400°W, 5160 ft, 23 July 2005, Ahart 12185 (CHSC); Small meadow near a small wash between the curve and below the bridge on old highway 80, east of Donner Pass and Donner Summit, 39.6521°N, 120.3169°W, 6767 ft, 31 July 2005, Ahart 12227 (CHSC); North of Hwy 20 about 8.2 miles west of I-80 ramp at intersection with road 20-16, 39.3171°N, 120.7239°W, 1617 m, 11 July 2016, Johnson 16-015 (BRY); Placer County, Cisco, 25 June 1910, Hall 8712 (UC); Rainbow, north of Cisco, 5700 ft, 23 June 1946, Rose 46201 (UC); Strawberry flat, the Henderson ranch, near Indian Creek, T15N R10E S23 SW1/4 of SW1/4, 3280 ft, 24 May 1969, Kawahara 870 (CAS); South facing slope of pyroclastic flow overlooking the North Fork of the American River, just off Sawtooth Ridge Road ca. 1.1 mile west of Dawson Spring, 39.2179°N, 120.6227°W, 1670 m, 3 June 2014, Johnson et al. 14-028 (BRY, JEPS); Along Forest Hill Road, ca. 0.2 miles northeast of NF-66 (Humbug Canyon Rd.), 39.1605°N, 120.6618°W, 1578 m, 3 June 2014, Johnson et al. 14-048 (BRY, JEPS); Off of Sugar Pine Road (NF10) enroute to Sugar Pine Reservoir, ca. 3.6 miles from Forest Hills Road, 1181 m, 39.1239°N, 120.7588°W, 9 June 2015, Johnson 15-013 (BRY); 50 yards northeast of the small natural lake, on the east side of the paved road to Lake Valley Reservoir, about 1/4 mile east of Yuba Gap and Highway 80, 39.3158°N, 120.6039°W, 5840 ft, 22 July 2002, Ahart 9896 (CHSC); Plumas County, south of Cascade and Lava Top, access via FS road 21N22YA, 39.6827°N, 121.1665°W, 1402 m, Johnson & Ahart 15-023 (BRY, JEPS, RSA); Along Lumpkin Ridge-La Porte Rd, ca. 6.9 miles northeast of junction with Golden Trout Crossing, 39.6982°N, 121.0783°W, 1541 m, 10 June 2015, Johnson & Ahart 15-030 (BRY, JEPS, RSA); About 1/4 mile north of Lumpkin Ridge Road, on Lumpkin Ridge, about 4 air miles northeast of Camp 18, 39.6856°N, 121.1061°W, 5013 ft, 3 July 2006, Ahart 12905 (CHSC, JEPS); North side of Onion Valley, east of Quincy La Porte Road, about 1 mile northwest of Pilot Peak, T22N R10E S5 SE1/4, 6000 ft, 13 September 1995, Ahart 7640 (CHSC); About 100 yards north of the paved basalt road, about 3.75 air miles northwest of Tamarack Flat, about 5.75 air miles northwest of Little Grass Valley Reservoir, 39.7615°N, 121.0980°W, 5507 ft, 9 July 2006, Ahart 12929 (CHSC); West edge of top of Goat Mountain, 0.7 km southeast of the southeast side of Little Grass Valley Reservoir, 39.7181°N, 120.9664°W, 1721 m, 6 July 2011, Janeway 10497 (CHSC); Tehama County, across fence on southwest side of Hwy 36 about 5.1 miles west of jct with Hwy 32, 40.3278°N, 121.4735°W, 1459 m, 26 June 2017, Johnson & Johnson 17-042 (BRY).

Hall 8712 (UC) describes this collection as faintly malodorous though we have not detected a scent ourselves in this taxon. The Shelton s.n. syntype of Gilia divaricata Torr. ex Gray belongs here.

When growing with N. divaricata, a subtle difference in habit and coloration is discernable, with N. torreyella somewhat more spreading, its primary inflorescence head closer to the ground, and the plants overall more anthocyanic (purple tinged); however, as these features can vary in both taxa, they should not be relied upon for determination. Instead, corolla coloration of both fresh and dried flowers as outlined in the diagnosis distinguishes N. torreyella from all of the species treated herein. This taxon also has the thinnest, most filiform branches of the species considered here.