Diagnosis.

Differs from Calystegia subacaulis Hook. & Arn. subsp. episcopalis Brummitt, by its clambering to strongly climbing stems (versus decumbent to trailing stems in Calystegia subacaulis subsp. episcopalis), larger leaves, 45–122 mm long, 30–96 mm wide mm long, subtending the peduncle (versus 23–28 mm long, 16–34 mm wide in Calystegia subacaulis subsp. episcopalis), with short, rounded, barely divergent to parallel basal lobes, or sometimes nearly without basal lobes, and essentially truncate (versus the basal lobes somewhat rounded to narrowly lanceolate and strongly divergent in Calystegia subacaulis subsp. episcopalis); Differs from Calystegia occidentalis (Gray) Brummitt subsp. occidentalis by its narrowly oblong, 2.5–5 mm wide sepals (versus oblong to oblong-ovate, 6–9 mm wide sepals in Calystegia occidentalis subsp. occidentalis), narrower corolla tube (basally) 4–5.9 mm wide measured at the most proximal visible point (versus 6–9 mm in Calystegia occidentalis subsp. occidentalis), an ovary that is glabrous on inside walls (versus a silky hairy vestiture inside of the ovary in Calystegia occidentalis subsp. occidentalis), and larger, 45–122 mm long, 30–96 mm wide, oblong-ovate to broadly ovate leaves subtending the peduncles (versus smaller leaves subtending the peduncle, 32–51 mm long, 33–66 mm wide, narrowly triangular to broadly ovate), and short, rounded, barely divergent to parallel basal lobes, or leaves that are nearly truncate at the base (versus leaves with divergent basal lobes of varying length that are 2-lobed to bipartite).

Type.

USA. California: San Bernardino County, City of Chino, SE of intersection of Edison Ave. and Oaks Ave., edge of Chaffey College Chino Campus, public right-of-way along powerlines. 33°59.822'N, 117°40.518'W, 206 m, 19 May 2012, A.C. Sanders, M.C. Provance, & T.A. Provance 40174 (holotype: UCR! [UCR-246125]; isotypes: ARIZ!, CAS!, K!, MO!, NDG!, NY!, RSA!, SBBG!, SD!).

Description.

Semi-herbaceous perennial vines, senescing in October, though with some stems and leaves persisting through winter. Aerial stems 1–3 m long, from shallow, creeping rhizomes and stolons (Fig. 2), climbing and twining, or clambering across shrubs, branching frequently, terete, with nonobvious longitudinal ridges, slender, tough and wiry, glabrous to sparsely hairy, in life dull grayish pink to light green with a rosy cast. Leaves alternate, membranaceous to chartaceus, glabrous to sparsely hairy, bicolored when mature green above, paler below, relatively flat and not folding along the midrib, but sometimes the basal half of the lamina slightly involute, and often having the basal lobes abruptly turned upward. Petioles on climbing stems 0.3–0.5 × length of lamina, e.g. about 14–61 mm long, but often longer relative to lamina length on emergent leaves; lamina of climbing stems 45–115(–122) mm long, 30–80(–96) mm wide, oblong-ovate to broadly ovate, but narrowly oblong on the sterile branchlets and on stems distal to the flowering axils, base cordate, with short, rounded, parallel or barely diverging basal lobes, sometimes essentially without basal lobes and nearly truncate, apex obtusely rounded, sometimes subacute, minutely apiculate; emergent leaves from rhizomes and on trailing stems variable in shape, but usually broadly oblong to oval or orbicular, sagittate, with short lobes, or lobeless and rounded to the petiole, apex broadly rounded; lamina venation obscurely pinnate, but with 2–4 lateral veins from the base. Inflorescences axillary, flowers usually solitary, rarely 2–3(–4)-flowered; pedicels 1–30 mm long, peduncles 18–63 mm long; bracts 2, attached (1–)2–3(–4) mm below the calyx, ascending, subopposite, 5–14 mm long, 1–2.5(–3.5) mm wide, narrowly elliptic to narrowly oblanceolate, obtusely pointed, ± flat, with a raised midvein, glabrous to scantly puberulent. Flowers perfect; sepals 5, entire, graduated, narrowly oblong to lanceovate, green with a rosy blush, short-ciliate, inner sepals 11–15 mm long, 3.5–4 mm wide, the lower portion tightly appressed to mature fruit, outer sepals 8–11 mm long, 2.5–5 mm wide, apices ± acutely rounded, mucronulate; corolla funnelform, 27–45 mm long, base of visible tube 4–5.9 mm wide, white (sometimes appearing light yellow in herbarium specimens), with 5 externally pigmented interplicae (midpetaline bands or longitudinal stripes), these very light-yellow, more rarely reddish-purple (Fig. 3), glabrous externally, or rarely, conspicuously hairy adjacent to pleats in the basal third of the corolla, the hairs yellowish, lobes 5, very short, each with a concentrated area of minute hairs along the margin; stamens 5, equal; filaments 18–21 mm long, fused to the corolla tube ± 7-9 mm of that length, glandular hairy along the proximal margins; anthers 4–4.5 mm long, white, barely reaching the base of the stigmas; pistil glabrous both internally an externally; style 16–21 mm long, glabrous, or with a few glandular hairs near the base; stigmas 2, cylindrical, ± 3 mm long, asymmetric, with one axially oriented, and the other ascending; nectary crenate-coronoid. Pollen white to cream, with circular perforations discernible at 60 X. Fruit dry capsule, indehiscent to tardily dehiscent from tip to base, globose, 9–10 mm in diameter, glabrous or obscurely minutely pubescent apically. Seeds 1–4 per capsule, ca. 4 mm in height and 3.5–4 mm in width, ± angular-ovoid, and depending on the number of developing seeds, nearly black to dark brown and tan-speckled, hilar region purplish, finely granular.

Distribution.

Calystegia felix is endemic to the inland basins of the Los Angeles, San Gabriel, and Santa Ana river watersheds in Southern California, at between 40 and 208 meters elevation. The species has not been seen in Los Angeles County since 1902. Six occurrences are known, all of them in the City of Chino, in San Bernardino County (Fig. 4). The occurrences have a spatial separation ranging from 0.3–2 km. The easternmost occurrence is just west of Euclid Avenue, close to Chino’s border with Ontario and Eastvale. The westernmost occurrences are on alluvial terraces above Chino Creek, coming within several meters of the City of Chino Hills.

Phenology.

Flowering begins in late March, and is heavy until early August, with flowering thereafter decreasing through late September. In 2011 and early 2012, inflorescences on the only plants known at that time had solitary flowers. During mid-May of 2012, inflorescences at that site were observed to be two or three-flowered, and rarely solitary. It is not certain whether flower number increased as the season progressed, or if flowers during the later visit were originating on vines of a different genet. Only solitary flowers were seen at the sites discovered in 2013. Ripe seeds have been collected from early June until late October. Fruit with small holes indicative of seed predation by bruchid beetles have been found (Provance, pers. obs.). Small, senesced, nodding, sterile, apetalous flowers, mostly near ground level, have recently been noticed on some plants. We observed similar flowers on herbarium specimens of a few other species of Calystegia. It is unknown if these flowers are apetalous developmentally, or if the corollas were lost to insect predation. More in-depth study of this condition is needed.

Additional specimens examined.

USA. California. San Bernardino County: Chino Creek south of Ontario, climbing in trees, 500 ft., 30 May 1917 (fl), I.M. Johnston 1274 (RSA, POM, UC); City of Chino, 33°59.823'N, -117°40.537'W, 206 m, SCE right-of-way, just northeast of Chaffey College, southeast corner of the intersection of Edison Rd. & Oaks Ave., 11 May 2011, M.C. Provance 17214 (UCR); same location, 14 May 2011, M.C. Provance 17351 (UCR, UC, DAV, NDG); same location, 25 Mar 2012, M.C., J.M., & T.A. Provance 17430 (UCR, WIS); West Chino, east of Chino Creek, 33°59.17'N, 117°42.38'W (± 300 m), 190 m, planter bed in public parking area, 31 May 2013, M.C. Provance 17525 (UCR, to be distributed); West Chino, east of Chino Creek, 34°00.18'N, -117°43.31'W (± 300 m), 208 m, planter bed in public parking area, 3 June 2013, M.C. Provance 17526 (UCR, to be distributed); West Chino, Highway 71 – Grand Avenue ramp, 33°59.44'N, -117°43.30'W (± 300 m), 205 m, Highway 71 and an adjacent planter bed in a public parking area, 11 June 2013, M.C. Provance 17527 (UCR, to be distributed); West Chino, 33°59.63'N, -117°43.18'W (± 300 m), 200 m, planter bed in a public parking area, 11 June 2013, M.C. Provance 17528 (UCR, to be distributed); East Chino, planter bed along public sidewalk near southeast corner of Buckeye Street and Fern Avenue, 33°59.65'N, -117°39.24'W (± 300 m), 206 m, 11 June 2013, M.C. Provance 17529 (UCR, to be distributed); City of Chino, SE corner of Edison Ave. and Oaks Ave., near entrance to Chaffey college campus, ca. 2.5 mi N of Chino Creek (Prado Basin), irrigated landscaped area adjacent to ruderal grasslands, 17 May 2011, J.M. Wood et al. 4092 (K not seen, RSA not seen). Los Angeles County: Rivera [historic town, later part of Pico Rivera, misspelled “Riveria” on Davidson’s herbarium label, and misspelled “Riviera” in Davidson and Moxley 1923], “Common in most grounds [moist grounds—a phrase Davidson often used on herbarium labels]” (Davidson 1909), “Very common on stream banks [either the Rio Hondo, or a small unnamed stream running through McCampbell and Downey Road, c. 0.5 km west of Rivera] at Riviera [Rivera] and on the Los Angeles and San Gabriel Rivers in that vicinity” (Davidson & Moxley 1923), 1 May 1902, A. Davidson 1892 (RSA [RSA-394817]); Near University Station [historic train station in S. Los Angeles at 43^rd St. and Vermont Ave. (Grace 2007)], Los Angeles, 1899, A. Davidson 2144 (RSA [RSA-394819] [mixed collection with Calystegia sepium]).

Discussion.

Taxonomy: Although arguments to maintain Calystegia have been weakened by recent molecular studies, we describe this new species as such, pending molecular phylogenetic studies that sample more thoroughly across both Calystegia and Convolvulus. Although their flowers are not similar, it is noteworthy that few vegetative characters seem to separate Calystegia felix from the weed Convolvulus arvensis L. The only vegetative feature we currently know that can reliably be used to tell these taxa apart is the cross section of the stem, which is angular in Convolvulus arvensis, and terete with weak longitudinal ridges in Calystegia felix. There may be differences in leaf venation, but that will require additional study. Unfortunately, Convolvulus arvensis is abundant throughout the Chino area, and occurs at several of the Calystegia felix sites.

While a definitive treatment of the entire Calystegia sepium complex has not been published, the best defining features of this group are the large bracts which immediately subtend, and often enclose the calyx, and have conspicuously netted venation. It is a taxonomically difficult complex that may include over twenty Calystegia sepium subtaxa, some additional closely related species, and their subtaxa (Stace 1961, Brown et al. 2009). So defined, all of the original material for Convolvulus binghamiae, including the lectotype at UC (Brummitt et al. 2012), is clearly referable to this complex. The epithet binghamiae is sometimes applied to specimens from Southern California with clasping bracts that only partly cover the sepals, and have leaves with barely divergent basal lobes, but that are otherwise inseparable from Calystegia sepium. All of the original material of Convolvulus binghamiae is from a salt marsh that once occurred in Santa Barbara. The lectotype has only one flower (Fig. 5), which has a bract that may be the smallest found on any of the original material. Nonetheless, the corolla has a broad base, as seen in all members of the sepium complex. Moreover, leaves from the same sheet (Fig. 5 and Fig. 6) are consistent with many specimens attributable to the Calystegia sepium complex. The bracts among the original material range from 7 to 13.8 mm long and 3.1 to 9.1 mm wide, and in their fully developed state are broadly lanceolate to broadly ovate. Inflorescence bracts in Calystegia felix have a similar range in length, but are much narrower at 1 to 3.5 mm in width, and usually lack a conspicuous network of veins. Most bracts in the Convolvulus binghamiae original material are in every sense typical of the Calystegia sepium complex. Interestingly, some of the largest bracts are associated with flower buds: in one case (Fig. 7), some of the bracts of the flower buds are larger than the bracts of the open flower on the same sheet. Finally, the corolla tubes (measured at the base of the sepal lobes) in the Calystegia binghamiae original material are over 8 mm wide. In Calystegia felix the lower tube of the corolla is narrow, ranging from 4 mm to about 6 mm in width. Calystegia felix is clearly not part of the Calystegia sepium complex, and represents a new, unrelated, and previously undescribed taxon.

Specimens of Calystegia felix were included in Convolvulus binghamiae by Davidson in his list of new records for Los Angeles (1909) and by Davidson & Moxley in their flora of Southern California (1923). When Jepson made the combination Convolvulus sepium var. binghamiae (Greene) Jepson, he was very particular in his application of the name, stating, “Santa Barbara; a distinct localized variety, rarely collected”. Under Convolvulus sepium var. pubescens, Jepson (1939) cites a Chino specimen (Condit s.n.) that we have seen, and which is equivalent to material typically ascribed to Calystegia sepium subsp. limnophila in Southern California (and elsewhere). While it is possible that Jepson had seen a collection of Calystegia felix at some point, it is not obvious where he would have placed such a collection in his 1939 treatment.

In 1945, Abrams annotated one sheet of Johnston’s Calystegia felix collection at RSA as Convolvulus binghamiae, probably while preparing his Illustrated Flora (1951). The illustration of Convolvulus binghamiae in this flora seems to be Calystegia felix, which is incongruent with his treatment, since the geographic distribution given by Abrams for Convolvulus binghamiae excludes all extant and historic occurrences of Calystegia felix. Brummitt (1993) applied Calystegia sepium subsp. binghamiae (Greene) Brummitt, to plants of the northern and central South Coast between sea level and 20 meters elevation, which excludes collections from Chino. In Brummitt et al. (2012), the author’s recognize the similarity of material we refer to Calystegia felix to the illustration in Abrams flora, noting, “A good illustration of the latter may be seen in Abrams (e.g., Fig. 3855, 1951)”. However, they propose that the drawing represents a phenotypic variant of their proposed Calystegia binghamiae (Brummitt) Brummitt. The misidentified collections at RSA and the illustration in Abrams of what was actually an undescribed species seems to have influenced the search image of at least some local botanists attempting to rediscover Calystegia sepium subsp. binghamiae.

Philip A. Munz annotated a Johnston collection at RSA as Convolvulus purpuratus Greene in 1931, thus clearly including Calystegia felix in his concept of Convolvulus purpuratus. In his Southern California Manual (Munz 1935) he listed Chino as a locality for this species. Among many differences, Calystegia purpurata (Greene) Brummitt subsp. purpurata can be readily separated from Calystegia felix by its equal, evenly inserted sepals.

The number of flowers per inflorescence, corolla pigmentation, external corolla vestiture, and the vestiture of leaves and stems vary in Calystegia felix. Whether this variation is influenced more by genetics or environmental factors remains to be studied. Heterophylly is profound in Calystegia felix, and generally manifests as narrower lamina on sterile twining stems, instead of the larger ovate to oblong-ovate leaves of reproductively active stems. There seems to be a tendency towards rounder leaves with longer petioles on emergent stems and sometimes trailing stems. Calystegia felix is similar to other species in the genus with small, somewhat remote bracts, and graduated sepals. Several morphological characters are used to compare four of those species with Calystegia felix (Table 1). Leaf parameters alone are often insufficient for the identification of Calystegia, but fortunately, several other characters in addition to leaf shape, differentiate Calystegia felix from other species of Calystegia.

At first glance, Calystegia felix looks most similar to Calystegia occidentalis (Gray) Brummitt subsp. occidentalis, since both taxa have a similar clambering or climbing habit, similar bracts inserted approximately the same distance below the calyx, and potentially produce multiple flowers in inflorescences. However, Calystegia felix differs from Calystegia occidentalis by its narrower sepals, narrower corolla tube, internally glabrous ovary, and larger oblong-ovate to broadly ovate leaves. The leaves subtending peduncles of Calystegia felix have short, rounded, barely diverging to parallel basal lobes. Sometimes, Calystegia felix leaves are nearly truncate at the base. This easily differentiates Calystegia felix from Calystegia occidentalis, which has lamina basal lobes that are of varying length, but divergent, and usually 2-lobed or bipartite. Calystegia felix also looks like Calystegia subacaulis Hook. & Arn subsp. episcopalis Brummitt. Both taxa have slender, but tough and wiry stems, corolla tubes that narrow toward the base, narrow sepals, and an ovary that is glabrous both internally and externally. It differs from Calystegia subacaulis subsp. episcopalis by its strong climbing habit, and much larger leaves that differ considerably in basal lobe morphology.

The similarities between Calystegia felix and Calystegia subacaulis subsp. episcopalis tend to be less readily apparent than the similarities between Calystegia felix and Calystegia occidentalis subsp. occidentalis. However, the characters shared seem not to be widespread in the genus. For example, while ovaries of Calystegia felix sometimes have a small number of minute hairs toward the apex, they are essentially glabrous externally. They are also glabrous internally. Though we have had only one specimen of Calystegia subacaulis subsp. episcopalis upon which we have been able to conduct detailed flower dissections (F. Bowcutt 2163 [UCR]), we are especially intrigued by the ovaries of this collection, which are glabrous both internally and externally. We have seen this combination of characters only in Calystegia felix, and similarities such as these might indicate that the two taxa are more closely related than their superficial appearances suggest.

Ecology: The six known occurrences are associated with somewhat poorly drained alkali silt loam (SoilWeb 2013), on a floodplain with an average slope of just over 1% (Lewis Publishing Company 1890, SoilWeb 2013). The local soils have developed primarily from the accumulated granitic alluvium that was washed out of the San Gabriel Mountains during episodic flood events (Hilgard 1902). Historically, there were a number of springs near the Calystegia felix occurrences, and the springs of the plains and basins and their accompanying vegetation, typically marshland and wet meadows, were known as ciénegas (Schuyler 1880, Mendenhall 1908). In Southern California the use of the word ciénega always implied the presence of a spring, unlike in some other parts of the American Southwest (e.g. Hendrickson and Minckley 1985). In the earliest known general description of ciénegas in the Chino Basin, Schuyler (1880) emphasized that ciénega was the only word commonly used to indicate its springs and associated habitat. In the Chino Basin, there were two (Hall 1888a, 1888b) or three (Tait 1911) main groups of ciénegas located a very short distance west to southwest, south, and southeast of Chino (Tait 1911). The perimeter of the Chino Artesian Spring Belt was roughly triangular, and its location in the current landscape is easily derived from the early maps. The east and west vertices were near the Chino Creek and Mill Creek emergences respectively. A third vertex would be near the south side of Prado Basin. These boundaries coincide well with the historical limits of “moist land” as mapped earlier by H. B. Martin (1887–1889). Mendenhall (1908) estimated the area of the artesian belt and associated moist soil as 23 sq. miles prior to 1904. Various aspects of the hydrology and geology of the Chino Basin ciénegas have been summarized (e.g. Truman 1874, Schuyler 1880, Hall 1888b, Lewis Publishing Company 1890, Shinn 1898, Mendenhall 1905, 1907, 1908, Hilgard and Loughridge 1906, 1908, Troxell 1957).

Historically, the water table in the vicinity of the artesian spring belt was 6–35 feet below ground (Lewis Publishing Company 1890) The soils within the spring belt, which are largely alkali silt loams, retained moisture throughout much of the year, and as a consequence were extraordinarily important to Southern California agriculture (e.g. Peffer 1894, Shinn 1898, Nelson 1917). Based on soil maps, four of the Calystegia felix occurrences are on Chino silt loam. Both of the occurrences that are not on Chino Silt Loam, one on Grangeville fine sandy loam, the other on Hilmar loamy fine sand, are less than 30 feet from Chino silt loam according to soil maps (SoilWeb 2013). While Calystegia felix occurrences seem to be strongly associated with Chino silt loam; an analysis of soil at occupied sites has not been performed.

On Edison Rd., Calystegia felix was discovered in a sidewalk tree basin on Chino silt loam. In that area, the soil is pale gray, with occasional small patches of fluffy salt crust. Disturbed alkali playa habitat was observed nearby, with Heliotropium curassivicum L., Heliotropium europaeum L., Cynodon dactylon (L.) Pers., Chenopodium berlandieri Moq., Malvella leprosa (Ortega) Krapov., Convolvulus arvensis L., and Amaranthus palmeri S. Watson. Also nearby was a sparsely vegetated earth-bottom ditch with Conyza and Lepidium strictum (S. Watson) Rattan, and old fields with Secale cereale and a diverse group of weedy native and introduced forbs. Native plant species documented within 400 m of the Calystegia site include: Amaranthus palmeri, Ambrosia psilostachya DC., Amsinckia sp., Atriplex serenana Abrams, Baccharis salicifolia (Ruiz and Pav.) Pers., Chenopodium berlandieri, Epilobium brachycarpum C. Presl., Epilobium ciliatum Raf., Fraxinus velutina Torr., Pseudognaphalium californicum (DC.) Anderb., Heliotropium curassivicum, Heterotheca grandiflora Nutt., Malacothrix saxatilis (Nutt.) Torr. & A. Gray, Malvella leprosa, and Solanum americanum Mill.

Although seeds and rhizomes can be moved around in many ways, we contend that invoking accidental transport of stem fragments or seed by humans is not the most parsimonious explanation for the presence of Calystegia felix in the City of Chino, since the species is known nowhere else. While we have no direct proof, we think the recently discovered Calystegia felix populations represent plants that have emerged from latent, long-lived seed banks or roots following a return to “moist soil” conditions (Figs 8, 9), similar to those in the historical record. Buried seeds of Calystegia sepium have retained high levels of viability after 39 years (Bond et al. 2007), and Calystegia felix may have similar longevity. If changes in soil moisture regimes are occurring (i.e.becoming wetter), horticultural practices within the urban environment are likely the cause. We have not investigated soil moisture in Chino experimentally, but we observed an apparent moisture gradient. The success we have had locating new occurrences of this rare plant in developed areas contrasts sharply with our failure to locate occurrences in undeveloped visually drier areas. While we are not sure of the significance at this point, it seems noteworthy that each of the sites currently supporting Calystegia felix were, based on aerial images (Google Earth V.2.1.6014b), completely stripped of their vegetation at some point between 4 and 11 years ago).

Historical information and early herbarium collections suggest that the Chino Basin originally had vegetation of wet meadow and alkali meadows dominated by Anemopsis californica (Nutt.) Hook. & Arn., with perennial grasses, such as Elymus triticoides Buckley, Sporobolus airoides (Torr.) Torr., and Distichlis spicata (L.) Greene, and herbs such as Trifolium willdenovii Spreng., Trifolium wormskioldii Lehm., and Helianthus annuus L. In addition, there were small bodies of open water, alkali and freshwater marshes, alkali scrub, alkali grassland, alkali playa, moist stream banks, and willow thickets. There were also phreatophytic woodland communities of Salix, Populus, and Platanus racemosa Nutt. (Truman 1874). The spring-belt wetlands were collectively referred to as “ciénega-lands” (e.g. Hilgard 1889). Common sunflower (Helianthus annuus) is frequently mentioned in the early literature as a common species on alkali soils in the Chino Basin, and was considered indigenous (e.g. Davy 1898). The topography just north of the Santa Ana River was reportedly hummocky (Nelson 1917), and may have been supportive of vernal pools. Most fine-scale relief in the basin has probably been lost to disking and grazing cattle, but the north part of the ciénega belt was reportedly rather smooth. Mendenhall (1905) commented:

“The lands just above this [above the ciénega-lands] are flat and often ill drained. The waters rising and evaporating here, under the influence of the effective southern sun, leave behind them their salt content, and thus alkali lands may result”

Thus, much of the landscape represented a mosaic of ciénega and ciénega-creek associated palustrine communities. The historical natural vegetation of the City of Chino cannot easily be envisioned because of past and current development. For example, a satellite of the University of California Agricultural Experiment Station called the “Ten Acre Tract” used to be in Chino and experiments related to growing crops on alkali soil were conducted there. This property was described as being dominated by Anemopsis californica (Hilgard & Loughridge 1896), which indicates that it was likely alkali marsh. The Ten Acre Tract is now occupied by industrial buildings and offices. However, taxa highly indicative of alkaline marsh and alkaline meadow have persisted in unusual places. For instance, we documented a number of Anemopsis californica persisting in plantings of Hedera helix along a sidewalk in northeast Chino near the Ontario border, just within the mapped historical limits of moist ground. The following year we found Calystegia felix growing in a sidewalk planter across the street from the Anemopsis site, in similar urban landscaping. We think other remnants of the ciénega flora may persist in Chino.

Conservation: Calystegia felix is endemic to Southern California, extirpated in Los Angeles County, and now likely confined to the Chino Basin in San Bernardino County. It is doubtless at high risk of soon becoming extinct in the wild. This is due to hydrological changes in the Chino Basin, including the paving of streams, lowering of the water table, and loss of ciénega habitat, including vegetation associated with marshes, meadows, grasslands and alkaline playas; and encroaching commercial, industrial, residential developments, and public works projects. Large areas of habitat have already been transformed. Six extant occurrences are now known, with an estimated 200 ramets emerging in 2013 at a single location near Chino Creek. However, those plants likely represent clones, as do the about 50 ramets at the other sites. Based on there being few known populations, a limited overall distribution, and a small number of individuals in existence, we suggest a conservation status of Critically Endangered (CR). Upon discovering the plants along Edison Road, it was obvious they were in imminent danger of being destroyed by impending grading and trenching for the burial of high-voltage power lines. We initially thought that these plants represented a single clone, but two ramet-specific flower color morphs, seed production, and spatial separation of clusters of emergent stems, suggest that two or more genotypes are present. Over the short term, Rancho Santa Ana Botanical Gardens has been contracted to conduct ex-situ propagation of rhizomes from the Edison Road population, and a few other plants are being cultivated in private and institutional gardens.