Fissidens asplenioides |
Fissidens osmundioides |
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asplenium fissidens moss |
osmund fissidens moss |
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Habit | Plants to 250 × 4 mm. | Plants 2–21 × 2–3 mm. |
Stem | unbranched and sparingly branched; axillary hyaline nodules weak; central strand present. |
sparingly branched; axillary hyaline nodules absent; central strand present. |
Leaves | in as many as 25 pairs, often undulate, mostly lingulate, rounded to obtuse to broadly acute, sometimes apiculate, to 4 × 0.5 mm; dorsal lamina narrowed proximally, ending before or at insertion, not decurrent; vaginant laminae 1/2–3/4 the leaf length, unequal, minor lamina of most leaves rounded and free distally, or narrowed distally and ending on or near costa; margin ± entire to crenulate-serrulate, sometimes unevenly so distally, elimbate except for a weak limbidium in the proximal parts of vaginant laminae, limbidial cells 1-stratose; costa ending several cells before apex, oblongifolius-type, distal part of leaf in transverse section showing enlarged cells arranged in a single row; laminal cells of dorsal and ventral laminae 1-stratose, distinct, smooth, lenticularly thickened but appearing bulging, firm-walled, irregularly hexagonal, 7–12 µm long; juxtacostal and interior proximal cells of vaginant laminae 1-stratose, smooth, plane, quadrate to ± oblong, larger; medial marginal cells of vaginant laminae ± elongate, oriented obliquely. |
in as many as 20 pairs, obovate to lanceolate, usually widest proximal to the middle, broadly acute to obtuse, often apiculate, 0.7– 2 × 0.3–0.7 mm; dorsal lamina rounded-truncate proximally, ending at or sometimes before insertion; vaginant laminae ± 1/2–3/4 the leaf length, ± equal, minor lamina ending on or near margin; margin crenulate throughout or evenly serrulate distally, elimbate; costa ending 2–14 cells before apex, taxifolius-type; lamina cells 1-stratose, distinct, smooth, bulging, firm-walled, ± hexagonal, 10–18 µm. Sexual condition dioicous; perigonia and perichaetia on elongate stems. |
Seta | to 6 mm. |
2–2.5 mm. |
Sexual condition | dioicous; perigonia and perichaetia on elongate stems; naked archegonia at times in axils of distal leaves. |
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Capsule | theca ± erect, radially symmetric to slightly arcuate, bilaterally symmetric, to 1.5 mm; peristome taxifolius-type; operculum ± as long as theca. |
theca erect, bilaterally symmetric, to 1 mm; peristome taxifolius-type; operculum 1 mm. |
Calyptra | cucullate, smooth, 1–1.7 µm. Spores 7.5–12 µm. |
mitrate, smooth, 1.5 mm. |
Spores | 16–23 µm. |
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Sporophytes | 1–2 per perichaetium, orange-red. |
1 per perichaetium. |
Fissidens asplenioides |
Fissidens osmundioides |
|
Habitat | Sandstone ledges and crevices in moist ravines and grottoes, usually along streams and waterfalls | |
Distribution |
AL; GA; KY; LA; MS; NC; SC; Mexico; Central America; South America; West Indies; Asia; Africa; Atlantic Islands (Macaronesia); Pacific Islands (New Zealand); Australia |
AK; AL; AR; CO; GA; IA; ID; IL; IN; KS; KY; MA; ME; MI; MN; MO; MT; NC; NH; NJ; NY; OH; OK; OR; PA; TN; VA; VT; WA; WI; WV; AB; BC; MB; NB; NF; NS; NT; NU; ON; QC; YT; Greenland; Europe; Asia |
Discussion | Fissidens asplenioides, usually a robust species, is recognized by leaves typically curled tightly inward from the tips when dry, a minor lamina that in most leaves is rounded distally and attached more or less only along costa, lenticularly thickened dorsal and ventral laminal cells, elongate medial marginal cells of the vaginant laminae oriented obliquely, and oblongifolius-type costa which in the distal part of the leaf in transverse section shows a single row of enlarged cells. The oblongifolius-type costa, found in F. asplenioides and F. santa-clarensis, is unique to sect. Amblyothallia of subg. Pachyfissidens (R. A. Pursell and M. A. Bruggeman-Nannenga 2004). Subterranean, multicellular, irregularly globose, rhizoidal gemmae have been reported in Macaronesian specimens of F. asplenioides. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Fissidens osmundioides is distinguished by its papillose rhizoids, evenly crenulate-serrulate leaf margin, broadly acute to obtuse and sometimes apiculate leaf apex, costa that ends well before the leaf apex, and terminal sporophytes. It is most apt to be confused with F. adianthoides, which has smooth rhizoids, irregularly serrate leaf apex, a band of lighter marginal cells, and sporophytes in the axils of proximal leaves. Generally in moist, shaded sites of acidic and basic rocks and boulders that are sometimes subject to spray, soil and humus in seepage areas, meadows, swamps, and fens, around bases of trees (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 27, p. 337. | FNA vol. 27, p. 340. |
Parent taxa | Fissidentaceae > Fissidens | Fissidentaceae > Fissidens |
Sibling taxa | ||
Name authority | Hedwig: Sp. Musc. Frond., 156. (1801) | Hedwig: Sp. Musc. Frond., 153, plate 40, figs. 7–11. (1801) |
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