Asplenium harrisii Jenman
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Authority
Mickel, John T. & Smith, Alan R. 2004. The pteridophytes of Mexico. Mem. New York Bot. Gard. 88: 1-1054.
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Family
Aspleniaceae
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Scientific Name
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Description
Species Description - Roots filamentous, wiry, not proliferous; rhizomes erect; rhizome scales bicolorous, center dark, strongly clathrate, margins narrow, lighter, lumina not occluded, 1-2 x 0.5 mm, entire; fronds clumped, to ca. 15 cm long; stipes greenish to tan, dull, usually less than 1.5 cm x 0.5 mm, ca. 1/10 of frond length, with occasional red-brown hairs ca. 0.2 mm long and rare red-brown hair-like scales 1.2 x 0.2 mm, adaxially with green wings ca. 0.1- 0.2 mm wide; blades membranaceous, 1-pinnate, 7-14 x 1.5 cm, linear, usually with flagelliform apices eventually bearing small buds; rachises greenish, dull, with rare red-brown hairs ca. 0.2 mm and reduced scales 1 or 2 cells wide and 0.2-1 mm long, both hairs and scales with enlarged, darkened apical cells, adaxially with green wings ca. 0.1 mm wide; pinnae dimidiate, medial pinnae oblong to almost round, mostly 15-30 pairs, 3-7 x 2.5- 4 mm, short-stalked to 0.5 mm, proximal 3-6 pairs gradually reduced nearly to rhizomes, pinnae similarly shaped but smaller distally, basiscopic sides cuneate and straight, acroscopic bases truncate, rounded at apices, margins of largest pinnae subentire to erose; veins 1- or 2-forked, ca. 3 pairs per pinna, evident on both sides of blades, tips evident adaxially; indument abaxially of scattered tan appressed clavate hairs 0.1–0.2 mm long on blades; sori 1 or 2 pairs per pinna, on both sides of midveins, sori on basiscopic sides ± parallel to lower margins; indusia ca. 1-1.5 x 0.3-0.5 mm, margins erose to entire; spores reniform; 2n=144 (Jam).
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Discussion
Type. Jamaica. Blue Mt. Peak, Harris s.n. [7474] (isotype K!).
The sole specimen from Hidalgo, from Plan del Ayacahuite, El Chico, “creciendo en las grietas de las pen˜as hu´medas,” is scrappy and without blade apices, so the identity is somewhat uncertain. If it is not this species, then it is possibly undescribed. Asplenium harrisii differs from other very small species in the A. trichomanes group, like A. soleirolioides, in having greenish or brownish, dull stipes and rachises. It is one of only a few other species of Asplenium in Mexico that have flagelliform apices, the others being A. soleirolioides, A. palmeri, and species in the A. radicans group. None of these appears to be closely related.
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Distribution
Epiphytic on tree bases (Chis) or in rock crevices in cloud forests; 2800 m. Mexico; Costa Rica (Hammel 19261, MO, UC); Jam.
Mexico North America| Costa Rica South America| Jamaica South America|