岩穴耳蕨 yan xue er jue

Plants evergreen. Rhizome ascending, 0.4-0.7 cm; roots brown when dry, up to 4.3 cm, 1-1.3 mm in diam., densely covered with scales; scales brown, linear or subulate, 1-1.3 mm. Fronds 3-8 per rhizome, 4-8 cm; stipe green, 1-3 cm, 1.3-1.9 mm in diam. at middle; basal stipe scales fuscous, dull, lanceolate, 2-4.5 × 0.5-1.2 mm, papery, margins slightly ciliate or erose, apices acuminate or caudate; distal stipe scales fuscous, dull, lanceolate with dilated bases, papery, margins ciliate, apices caudate. Lamina 1-pinnate, shiny adaxially, oblanceolate, 4-7 × 1-1.6 cm at middle, 1.3-1.7 cm wide at broadest part, contracted toward base, apex obtuse; rachis 1.2-1.6 mm in diam. at middle, without proliferous bulbils; scales of rachis fuscous, dull, lanceolate with dilated base, 1.8-4 × 0.4-1 mm at base, varying in size, papery, margins ciliate, apices caudate. Pinnae 6-14 pairs, approximate to often overlapping, basal two pairs 4-9 mm apart and strongly reflexed toward lamina base, alternate, deltoid-ovate, middle pinnae 5-7 × 4-6 mm, largest pinnae 5.3-7.5 × 4.2-6.3 mm and near lamina apex, sessile, acroscopic base rounded, basiscopic base and rachis often forming 20°-60° angle, apices obtuse, bases truncate, margins repand, not mucronate; abaxially scaly, adaxially glabrous; microscales on abaxial surface subulate with dilated bases (broad-type microscales), 0.5-1.1 mm, base 0.16-0.28 mm wide, with few tortuous cilia on margin of base; frond texture thinly leathery; venation pinnate; midrib slightly raised abaxially, flat adaxially; lateral veins free, 3 or 4 pairs from midrib per pinna, nearly opposite; each lateral vein dichotomous, slightly raised and distinct abaxially, indistinct adaxially. Sori terminal on veins of upper pinnae, 2-5 per fertile pinna, close to (ca. 0.7 mm from) pinna margin; indusia brown, ca. 0.7 mm in diam., membranous, erose. Spores orbicular in polar view, elliptic in equatorial view, ca. 40.9 × 53.7(48.9-59.2) × 44.4(39.8-49.1) µm (polar axis × long equatorial axis × short equatorial axis, respectively); perispore sculpturing cristate with numerous spinules shorter than 3 µm.

● Inside karst caves; ca. 700 m. S Guizhou (Libo).

Polystichum speluncicola is special in P. sect. Haplopolystichum in having broad-type microscales and deltoid-ovate pinnae. It is ± similar to P. dielsii, P. liboense, and P. minutissimum, but P. speluncicola has nearly leathery and close-set pinnae, and basal pinnae reflexed. In addition, P. speluncicola can be distinguished from P. dielsii by having lamina smaller, oblanceolate, apex obtuse, and with 6-14 pairs of pinnae, and sori fewer per pinna; from P. liboensis by having lamina oblanceolate and pinnae without hydathodes; and from P. minutissimum by having stature larger and lamina with 6-14 pairs of pinnae.