灰绿耳蕨 hui lü er jue

Polypodium scariosum Roxburgh, Calcutta J. Nat. Hist. 4: 494. 1844; Polystichum aculeatum (Linnaeus) Roth ex Mertens var. variiforme Hayata; P. eximium (Mettenius ex Kuhn) C. Christensen var. minus Tagawa; P. fibrillosum Ching; P. gemmiferum Tagawa; P. indochinense Tardieu & C. Christensen; P. tialooshanense Ching; P. variiforme (Hayata) Tagawa.

Plants evergreen. Rhizome ascending, short, thick, up to 4 cm in diam., upper part densely covered with dimorphic scales; large scales brown or partly castaneous, margins brown, ovate-oblong or ovate-lanceolate, up to 1.5 cm × 5 mm, thickly membranous, subentire, partly to mostly thickened, margins membranous, of different widths; small scales brown, lanceolate or narrowly lanceolate, membranous, sparsely toothed. Fertile fronds 0.7-2 m; stipe stramineous, 20-80 cm, 3-7 mm in diam. at base, scales gradually sparser and smaller upward, upper stipe with small scales only. Lamina bipinnate to 5/6 of lamina, grayish green, adaxially darker, various in shape, narrowly deltoid on fully developed plants, up to 1.2 m × 70 cm, not contracted at base, acuminate; lamina on small fertile plants broadly oblong-lanceolate, ca. 40 × 12 cm, base obviously contracted, bipinnate only below middle part, sometimes lamina 1-pinnate and only basal pinnae shallowly pinnatifid to pinnatifid, acuminate; rachis stramineous, scaly on both surfaces; scales small, rachis with 1 or 2 proliferous bulbils toward tip, bulbils densely covered with brown scales. Pinnate pinnae lanceolate or oblong-lanceolate, up to 16 pairs on large lamina, up to 35 × 8 cm, stalks of pinnae up to 1 cm, long acuminate, lateral pinnules up to 16 pairs on small lamina, largest pinnae ca. 8 × 3 cm, stalks of pinnae only ca. 1 mm, shortly acuminate, lateral pinnules 2 or 3 pairs only; 1-pinnate lamina long and narrow, 45-50 × ca. 12 cm; lateral pinnae up to 20 pairs, falcate-lanceolate, upward curved, up to 8 × 1.8 cm, acroscopic base obtuse-auriculate, basiscopic side obliquely dimidiate, apex acuminate; basal pinnae pinnatifid, upper pinnae shallowly pinnatifid to only incised; costa green adaxially, stramineous abaxially, scales densely clustered at base, rarely with proliferous bulbils on upper rachis. Pinnules dimidiate, large pinnules falcate-lanceolate or falcate-rhombic, apices acuminate or long acuminate, upward curved, shallowly pinnatifid, with lobes acute or obtuse, or sparsely toothed, teeth angled upward, obtuse, and coarse; pinnules up to 7 × 1.5 cm, auricles deltoid, acute, basiscopic bases cuneate or curved, pinnules of small lamina ovate-rhombic, margins only shallowly incised or undulate, apex acute; auricles short, obtuse, or indistinct, basiscopic margins curved, basiscopic proximal half entire, basal basiscopic pinnules of all pinnae often smaller, basal acroscopic pinnules sometimes larger and sometimes smaller; microscales light brown, thinly membranous, subulate; frond texture thinly leathery; venation bipinnate on both pinnules and upper pinnae, indistinct on both sides, veins free, rarely forked. Sori terminal or abaxial on veins of pinnae, submedial, often in 1 row on each side of midrib, up to 5(-7) pairs, but often 2 rows on each side of midrib on larger pinnules of large lamina, 2-4 pairs on auricles; indusia brown when mature, small, shallowly lobed, easily falling off. Spores reniform in equatorial view; perispore sculpturing plicate or reticulate with spinules.

Streamsides in broad-leaved evergreen forests; 200-1900 m. Guangxi, Guizhou, Hainan, Hong Kong, S Hunan, Jiangxi, S Sichuan, Taiwan, Yunnan, Zhejiang [S India, S Japan (Yakushima), Sri Lanka, Thailand, Vietnam].

In FRPS (5(2): 19. 2001), this species is referred to as Polystichum eximium (Mettenius ex Kuhn) C. Christensen.

Fraser-Jenkins (Himalayan Ferns (Guide to Polystichum), 24. 1997) argued that Polystichum scariosum has long been misidentified as P. eximium (Mettenius ex Kuhn) C. Christensen (= P. anomalum (Hooker & Arnott) J. Smith), a S Indian and Sri Lankan endemic. However, more studies are needed. Notably, there are several ploidy levels involved.