81. Asplenium sarelii Hooker in Blakiston, Five Months Yang-Tsze. App. VI: 363. 1862.
华中铁角蕨 hua zhong tie jiao jue
Asplenium blakistonii Baker; A. pekinense Hance var. foeniculaceum Christ.
Plants 10-23 cm tall. Rhizome short, erect or ascending, apex scaly; scales dark brown to black, narrowly triangular, 2-4(-6) × 0.3-0.7 mm, margins denticulate; scale base hyaline, cordate, with yellow-brown, unicellular hairs 1-5 × ca. 0.02 mm, similar to root hairs. Fronds caespitose; stipe 7-10 cm, semiterete, base dark brown abaxially, upward green, adaxially yellow-green, sulcate with pronounced supravascular ridge, with similar scales as on rhizome, reduced hairlike scales toward rachis or subglabrous; lamina triangular-ovate, 6-15 × 2.5-7 cm, base truncate, apex acute, tripinnatifid-tripinnate; pinnae 8-12 pairs, basal pairs subopposite to alternate, stalk 1-3 mm, sulcate but with median supravascular ridge adaxially; basal pinnae equal or slightly shorter than next, ovate-triangular, 1.5-4.5 × 1.5-3 cm, base nearly symmetrical, truncate to broadly cuneate, bipinnatifid-bipinnate, apex acute; pinnules 4-6 pairs, anadromous, basal pinnules ± equal in size, narrowly triangular to ovate, 5-20 × 4-7 mm, base asymmetrical, acroscopic side truncate, basiscopic side cuneate, stalk up to 1 mm or decurrent on costa, pinnatipartite-pinnate, apex acute; segments 3 or 4 pairs, linear, 1.5-5 × 0.5-2 mm, basal segments forked or up to pinnatisect with 2 or 3 ultimate segments, apex of segments with 2 or 3 teeth. Costa sulcate adaxially, with distinctly raised median supravascular ridge, veins raised adaxially, veins anadromously forked. Fronds thinly to firmly herbaceous when dry, green to grayish green, lamina subglabrous, average stomatal guard cell length 35-43 µm; rachis green, semiterete, adaxially sulcate with raised median supravascular ridge, with reduced scales or subglabrous. Sori 1 or 2 per ultimate segment, median to subterminal on acroscopic vein, near segment teeth but not reaching margin, subconfluent at maturity, subelliptic, 1-2 mm; indusia grayish green, subelliptic, membranous, entire, opening toward costule or central veinlet, persistent. Spores brown, perispore lophate (cristate), average exospore length 28-30 µm. Plants sexual diploids: 2n = 72*.
● In rock crevices; 300-1000(-2100) m. Anhui, Chongqing, N Guizhou, ?Henan, Hubei, Hunan, Jiangsu, Shaanxi, Sichuan, Zhejiang.
"Asplenium saulii" (Hooker & Baker, Syn. Fil., ed. 2, 216. 1874) is evidently a mere orthographic variant of A. sarelii.
Asplenium sarelii is endemic to C China. All reports of this species from outside China are erroneous and usually refer to the very similar tetraploid A. anogrammoides. Hybridization experiments, including cytological study of meiotic behavior in artificially produced hybrids (Lin & Sleep in K. H. Shing & K. U. Kramer, Proc. Int. Symp. Syst. Pterid. 111-127. 1989), and micromorphological study of type material have shown that A. sarelii is one of the parental species of allotetraploid A. anogrammoides; the other parent being diploid A. tenuicaule. These findings were confirmed by cytological and isozyme studies (Wang, Acta Bot. Sin. 45: 1-14. 2003). The morphological similarity between these taxa has led to great confusion, also with true A. pekinense, which is the autotetraploid that originated from true A. sarelii. In A. sarelii, the ultimate segments are less than 1.2 mm wide, the pinnae stalks less than 1 mm wide, and its pinnae are distant from each other and hardly overlap so that the frond silhouette is more open than in A. anogrammoides. Important differential characters are the chromosome number and the average exospore and stomata size. Identification based on morphology alone is very difficult when A. sarelii grows with A. pekinense and A. anogrammoides. At such locations, e.g., Wudang Shan (Hubei) and Huping Shan (Hunan), the sterile triploid hybrids, A. ×wudangshanense (A. pekinense × A. sarelii) and A. ×huawuense (A. anogrammoides × A. sarelii), are relatively common and recognizable by their aborted spores and often undeveloped sporangia. Asplenium ×wudangshanense Viane, Reichstein, Rasbach & Y. X. Lin, nothosp. nov. Type: China. Hubei: Wudang Shan, ca. 2050 m, Sep 1907, Silvestri 6 (pl. 5) (holotype, FI). Planta hybrida, inter parentes A. pekinense et A. sarelii quoad divisionem laminae atque pinnularum segmentorumque formam necnon dimensiones cellularum accessoriarum stomatum intermedia, ab eis sporis abortivis necnon chromosomatum numero triploideo (2n = 108, meiose trivalentibus 0-5, bivalentibus 33-37 et univalentibus 29-40) differt. Meiotic chromosome behavior in A. ×wudangshanense confirms that A. pekinense is the autotetraploid of A. sarelii. Meiotic chromosome behavior (Wang in K. H. Shing & K. U. Kramer, Proc. Int. Symp. Syst. Pterid. 133-134. 1989; loc. cit. 2003) in A. ×huawuense confirms that A. anogrammoides is allotetraploid and contains one chromosome set of A. sarelii. Asplenium ×huawuense Z. R. Wang ex Viane & Y. X. Lin, nothosp. nov. Type: China. Hubei, Wudang Shan, ca. 850 m, 18 Jul 1987, Z. R. Wang C843 (holotype, PE). Planta hybrida, inter parentes A. anogrammoides et A. sarelii quoad divisionem laminae atque pinnularum segmentorumque formam necnon dimensiones cellularum accessoriarum stomatum intermedia, ab eis sporis abortivis atque chromosomatum numero triploideo (2n = 108, meiose bivalentibus univalentibusque 36) differt. All of Z. R. Wangs new names (Wang, loc. cit. 2003) are nomina nuda and were not therefore validly published (Melbourne Code, Art. 38.1(a)).