Pellaea truncata

Pellaea truncata Goodd.
(Latin: truncus, cut off, = ending abruptly as if cut off straight across, truncate)

Local names: spiny cliff-brake

Plants to 40 cm tall; rhizome scales with 2 distinct colors, black in center with brown along margins; petioles dark brown, shiny; leaf blades usually 2-pinnate basally, 4–18 cm wide, somewhat dimorphic; rachis and costae glabrous; pinnae attached to rachis so that their tips point } straight out or slightly towards tip of leaf, mostly with 9–25 ultimate segments each, at least the basal pinnae with segments completely separate (pinnae truly pinnate); ultimate leaf segments narrowly oblong to oblong (variable in shape), apically mucronate (= with a short, small, abrupt pointed tip), leathery, glabrous; 2n = 58 (Windham 1993c). Rocky slopes on a variety of substrates, but usually not limestone; in TX known from the Trans- Pecos in Franklin Mts. (R.D. Worthington 9475, BRIT) and Hueco Mts. (Correll 13799, BRIT, TEX-LL) in El Paso Co., Cornudas Mts. (Correll & Johnston 24327, TEX-LL) and Quitman Mts. (McVaugh 8033, BRIT, TEX-LL) in Hudspeth Co., Davis Mts. in Jeff Davis Co. (T. Simpson 202, BRIT; Correll 33665, TEX-LL), and from the extreme w part of the Edwards Plateau in Val Verde Co. (Plank s.n., Dec 1891, Del Rio [well e of the Pecos River]—Correll 1956; Yarborough & Powell 2002); sw U.S. (AZ, CA, CO, NV, NM, TX, and UT); also n Mexico. Sporulating late spring–fall. [P. longimucronata Hook., P. wrightiana var. longimucronata (Hook.) Davenp.] This species has in the past often gone by the nomenclaturally invalid name P. longimucronata (Windham 1993c). Morphologically intermediate hybrids with P. wrightiana are reported to be “common in regions where the ranges of the two species overlap, but these [hybrids] are easily identified by their malformed spores” (Windham 1993c). Because of its rareness and limited distribution in the state, we consider this species to be of conservation concern in TX.

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