Corresponding author: Layne Huiet (
Academic editor: Jefferson Prado
A new species of
Huiet L, Lenz M, Nelson JK, Pryer KM, Smith AR (2015)
The genus
Of the four wide-ranging species, three
While investigating
Chromosome material of young sporangia was field-fixed in ethyl alcohol:acetic acid (3:1). Spore mother cells were stained with acetocarmine, and, using standard squash techniques, examined under a compound microscope. Meiotic cells were examined at diakinesis, metaphase I, and normal pairing of homologous chromatids was seen. The voucher is listed under paratypes.
Rhizomes short-creeping or ascending, usually buried in loose soil, 2–4 mm in diameter, sometime branching; stipes clustered, up to 10 fronds per 1 cm of rhizome length; rhizome scales (and those at stipe base) castaneous to dark brown, lustrous, concolorous, ovate to lanceolate, attenuate at tips, 1.5–5 × 0.3–0.6 mm, margins entire; fronds clustered, mostly (18–)30–60 cm long, arching, persisting (remaining green) through summer, fall, and into winter; older dead fronds remaining attached to rhizome behind new growth; stipes castaneous to atropurpureous, becoming blackish with age, sublustrous, sometimes slightly glaucous (especially proximally), terete, each with a single vascular bundle at bases, (10–)20–30 cm long, (0.6–)0.8–2.0 mm in diameter, ca. 1/2 the frond length, glabrous except at very bases; laminae ovate to deltate, 2–3 times pinnate (depending on size), mostly (12–)20–35 × (6–)15–20 cm, broadest at or just above the bases, tapering gradually to apices, costae (pinna axes) ascending mostly 30–50 degrees from rachis, pinnae acroscopically branched, basal acroscopic pinnule longer, more dissected, and at a greater angle with respect to costa than basal basiscopic branch (pinnae thus somewhat unequal-sided), laminae bluish green, often slightly glaucous; rachises castaneous to atropurpureous, glabrous, lustrous or slightly glaucous, terete to somewhat angled or obscurely sulcate adaxially (more so distally); pinnae of well developed laminae ca. 6–8 pinnate to bipinnate pairs below the 1-pinnate apical region (which is 3–5 cm long), decidedly alternate, stalked to ca. 2 cm (proximal pinnae); pinnulets (ultimate segments) obovate, flabellate, or rhombic, sometimes semicircular, non-articulate except on very old laminae (stalks not breaking cleanly, not cupule-like at their apex), mostly 1–2 × 1–2 cm (to 2 × 3 cm in sterile segments of juvenile fronds), cuneate at bases ca. 90–135 degrees (more narrowly cuneate bases on distal segments), occasionally pinnulet bases truncate and the pinnulets thus semicircular (especially proximal acroscopic pinnulet on well-developed pinnae), margins often cleft 1–4 mm, sterile pinnulets generally more incised than the fertile, 1–3 clefts per pinnulet, sterile margins thickened, whitish, shallowly crenulate distally, color of stalks gradually diminishing at base of pinnulets and passing slightly into pinnulet lamina; veins free, forking, in sterile laminae ending in small rounded crenulations (not in sharp teeth) of pinnulet margins, usually visible but only slightly raised, if at all, on both sides of laminae; indument lacking on both sides of laminae; idioblasts not apparent either abaxially or adaxially; sori 2–7 per pinnulet, confined to distal margins, sporangia borne on ± parallel veins on the strongly reflexed underside of the indusia (facing laminar tissue), mixed with sessile yellow-orange, cylindrical or clavate glands < 0.1 mm long; indusia mostly (1–)2–4 mm long, ca. 1 mm wide, entire or nearly so, oblong to slightly arcuate (not noticeably reniform), lacking hairs. 2n = 30 II.
Photographs of
Holotype of
Sporulates mid to late spring and most likely throughout summer.
It seems most appropriate to name this species
Shasta maidenhair fern.
We recommend a California Rare Plant Rank of 4.3, a watch list for plants of limited distribution.
U.S.A. California: Shasta Co.: 2.6 miles E of Nosoni Mountain on the west side of North Fork Squaw Creek, 2700 ft, 07 Apr 2009,
It was a surprise to discover that amongst the few herbarium collections of
Morphologically
The first collection of
It appears that the Shasta maidenhair fern is another narrow endemic found in the area surrounding Shasta Lake. This region is host to a number of endemic plants and animals, most likely because of its unique geology, age and climate. These include the Shasta salamander,
1 | Rhizomes stout, compact, short-creeping to suberect, usually 5–8 mm diam. (scales excluded); stipes mostly 1.5–3 mm diam. at bases; laminae palmate-pinnate (fan-shaped), proximal pinna pair 2–3-times basiscopically forked; pinnulets strongly inequilateral, 2–4 times longer than wide |
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– | Rhizomes relatively narrow, short- to long-creeping (occasionally more compact in |
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2 | Rhizome and stipe base scales golden brown or light brown; laminae usually 2-pinnate; pinnulets (especially sterile ultimate segments) cut or lobed often >1/4 or much more than (to 2/3) the way to base; dark color of stalks extending into base of ultimate segments; distal teeth of sterile segments usually >3 mm long, acute at tips; pinnulet margins at base diverging at 45–90°; sori (and false indusia) (2–)3–11 per pinnulet, generally < 5 mm long |
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– | Rhizome and stipe base scales dark brown or dark purplish brown; laminae 2–3-pinnate, larger fronds with proximal pinnae usually having at least 1 or 2 pairs of pinnules divided (i.e., laminae 3-pinnate proximally); pinnulets (especially sterile ultimate segments) cut or lobed usually <1/4 of the way to base; dark color of stalks extending into base of ultimate segments or ending ± abruptly at base of ultimate segments; distal teeth of sterile segments 1–2(–3) mm long, rounded or acute at tips; pinnulet margins at base diverging at 90–180(–240)°; sori (and false indusia) 1–5 per pinnulet, some generally > 5 mm long. | |
3 | Rhizomes short-to long-creeping, just below soil surface, stipe bases often > 5 mm apart; lamina tissue green; dark color of stalks ending ± abruptly at base of ultimate segments; ultimate segments often somewhat semi-lunate; mature fronds dying in late spring or early summer, completely dried and largely unseen in late summer, fall, and early winter; throughout California, but apparently rare in Shasta Co |
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– | Rhizomes short-creeping to suberect, often deeply buried, stipe bases < 5 mm apart; laminar tissue bluish green; dark color of stalks extending into base of ultimate segments; ultimate segments often somewhat rhomboidal; mature fronds persistent and evergreen through summer and into winter and following spring; Shasta Co., locally abundant |
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Note: a combination of characters must occasionally be used to separate
We thank the following herbaria and their staff for the processing and use of specimens and loans: UC, JEPS, DUKE and OSC. Thanks to D. Taylor and E. Alverson for additional collection data. We are profoundly indebted to J. Smith and E. Dean for their untiring support and assistance during fieldwork. Also thanks to E. Dean for the use of photographs and preparation of field notes. L.H. would like to thank C.J. Rothfels for technical help with figures and manuscript preparation. This work was supported by NSF grant DEB-1145614 to K.M.P. and L.H. We also thank the Shasta-Trinity National Forest for permit 038584.