Fissidens dubius |
Fissidentaceae |
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fissidens moss |
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Habit | Plants to 25 × 3.5 mm. | Plants tiny to robust. |
Stem | usually branched; axillary hyaline nodules absent; central strand present. |
, except for initial stages, growing from a 2-sided apical cell. |
Leaves | as many as 25 pairs, often undulate, oblong to lanceolate, obtuse to acute, often apiculate, to 3.5 × 0.7 mm; dorsal lamina truncate-rounded proximally, ending at insertion, not decurrent; vaginant laminae 2/3 the leaf length, ± unequal, minor lamina ending near margin; margin crenulate to crenulate-serrulate but unevenly serrate at leaf apex, elimbate; costa ending a few cells before apex to percurrent, taxifolius-type; laminal cells irregularly 2-stratose in dorsal and ventral laminae, ± obscure, smooth, bulging, firm-walled, rounded-hexagonal, 7–10 µm, 3–4 rows of marginal cells thinner, walls slightly thicker, forming a pale marginal band. |
distichous, equitant, complex in form, consisting of two vaginant laminae that clasp the stem, a ventral lamina located above the vaginant laminae, and a dorsal lamina that occupies the length of the leaf opposite the vaginant and ventral laminae; costa single, usually well developed, near center of leaf, sometimes reduced, absent or nearly so. |
Seta | to 11 mm. |
elongate. |
Sexual condition | dioicous; perigonia on short axillary branches and elongate stems; perichaetia on short axillary branches, mostly near proximal ends of stems. |
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Capsule | theca slightly inclined, slightly arcuate, bilaterally symmetric, to 1.8 mm; peristome taxifolius-type; operculum 1–1.4 mm. |
cylindric, peristome single, teeth 16, haplolepidous, endostomate, usually divided 1/2–2/3 their length, sometimes irregularly divided or undivided, sometimes reduced, (rarely absent). |
Calyptra | cucullate, smooth, 1.8 mm. |
cucullate. |
Spores | 13–20 µm. |
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Sporophytes | 1 per perchaetium. |
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Fissidens dubius |
Fissidentaceae |
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Habitat | Soil and humus, bases of trees, decaying wood, rocks and boulders in moist, shaded sites | |
Distribution |
AK; AL; AR; AZ; CA; CT; DE; FL; GA; IA; IL; IN; KS; KY; MA; ME; MI; MN; MO; MS; NC; NE; NH; NY; OK; PA; SC; TN; TX; VA; VT; WI; WV; NB; NF; NS; ON; QC; Mexico; Central America; West Indies; Europe; Asia; Pacific Islands
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Worldwide; mostly tropics |
Discussion | In contrast to Fissidens adianthoides, F. dubius has smaller, irregularly 2-stratose, obscure laminal cells. Subterranean, irregularly globose, multicellular rhizoidal gemmae have been reported for F. dubius as well as F. osmundioides and F. taxifolius in Europe and Japan. Z. Iwatsuki and T. Suzuki (1982) cited the occurrence of dwarf male plants (small perigonial stems located on the leaves of perichaetial plants) in Japanese specimens. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Genus 1, species 450 (37 in the flora). Fissidentaceae is recognized easily by its distichous and equitant leaves. This leaf form is closest to that of Bryoxiphium. The hepatic Diplophyllum is often confused with Fissidens. Relationship of the Fissidentaceae is with the Dicranaceae; both families have similar peristomes but differ principally in leaf structure. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 27, p. 340. | FNA vol. 27, p. 331. |
Parent taxa | Fissidentaceae > Fissidens | |
Sibling taxa | ||
Subordinate taxa | ||
Synonyms | F. adianthoides var. semicristatus, F. cristatus, F. cristatus var. winonensis, F. decipiens var. winonensis, F. floridanus | |
Name authority | P. Beauvois: Prodr. Aethéogam., 57. (1805) | Schimper |
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