Fissidens dubius

P. Beauvois

Prodr. Aethéogam., 57. 1805,.

Synonyms: Fissidens adianthoides var. semicristatus Grout Fissidens cristatus Lesquereux & James Fissidens cristatus var. winonensis (Renauld & Cardot) Grout Fissidens decipiens var. winonensis Renauld & Cardot Fissidens floridanus
Treatment appears in FNA Volume 27. Treatment on page 340. Mentioned on page 333, 335.

Plants to 25 × 3.5 mm. Stem usually branched; axillary hyaline nodules absent; central strand present. 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. Sexual condition dioicous; perigonia on short axillary branches and elongate stems; perichaetia on short axillary branches, mostly near proximal ends of stems. Sporophytes 1 per perchaetium. Seta to 11 mm. Capsule theca slightly inclined, slightly arcuate, bilaterally symmetric, to 1.8 mm; peristome taxifolius-type; operculum 1–1.4 mm. Calyptra cucullate, smooth, 1.8 mm. Spores 13–20 µm.

Habitat: Soil and humus, bases of trees, decaying wood, rocks and boulders in moist, shaded sites


V27 466-distribution-map.gif

N.B., Nfld. and Labr. (Nfld.), N.S., Ont., Que., Ala., Alaska, Ariz., Ark., Calif., Conn., Del., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., Maine, Mass., Mich., Minn., Miss., Mo., Nebr., N.H., N.Y., N.C., Okla., Pa., S.C., Tenn., Tex., Vt., Va., W.Va., Wis., Mexico, West Indies, Central America, Europe, Asia, Pacific Islands.


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.

Selected References


Lower Taxa

... more about "Fissidens dubius"
Ronald A. Pursell +
P. Beauvois +
N.B. +, Nfld. and Labr. (Nfld.) +, N.S. +, Ont. +, Que. +, Ala. +, Alaska +, Ariz. +, Ark. +, Calif. +, Conn. +, Del. +, Fla. +, Ga. +, Ill. +, Ind. +, Iowa +, Kans. +, Ky. +, Maine +, Mass. +, Mich. +, Minn. +, Miss. +, Mo. +, Nebr. +, N.H. +, N.Y. +, N.C. +, Okla. +, Pa. +, S.C. +, Tenn. +, Tex. +, Vt. +, Va. +, W.Va. +, Wis. +, Mexico +, West Indies +, Central America +, Europe +, Asia +  and Pacific Islands. +
Soil and humus, bases of trees, decaying wood, rocks and boulders in moist, shaded sites +
Prodr. Aethéogam., +
Fissidens adianthoides var. semicristatus +, Fissidens cristatus +, Fissidens cristatus var. winonensis +, Fissidens decipiens var. winonensis +  and Fissidens floridanus +
Fissidens dubius +
Fissidens +
species +