Macrocoma

(Hornschuch ex Müller Hal.) Grout

Bryologist 47: 4. 1944

Etymology: Greek macros, long, and kome, hair, alluding to long hairs on calyptrae of some species
Basionyms: Macromitrium sect. Macrocoma Hornschuch ex Müller Hal. Bot. Zeitung (Berlin) 3: 522. 1845
Treatment appears in FNA Volume 28. Treatment on page 43. Mentioned on page 38, 653.
Plants small, in mats. Stems creeping, branches ascending. Leaves closely erect-appressed, not contorted when dry, erect-spreading when moist, lanceolate to ovate-lanceolate, not rugose; margins entire; apex acute to narrowly obtuse [bluntly acuminate]; costa percurrent; basal laminal cells rounded to elliptic; distal cells rounded-quadrate, 7–12 µm, in vertical rows, smooth [papillose only over lumina]; marginal cells not distinct from basal. Sexual condition gonioautoicous; perichaetial leaves longer than branch leaves. Seta 4–6.5 mm. Capsule exserted, oblong-cylindric to fusiform, ± plicate distally or not, not constricted below mouth; stomata superficial; peristome single, of exostome or endostome; exostome teeth 16 blunt, short, papillose; or endostome basal membrane low, papillose. Calyptra mitrate, long elliptic-conic, basal lobes many, smooth, ± hairy, obscurely plicate, covering capsule. Spores isosporous, unicellular.

Distribution

se United States, Mexico, West Indies, Central America, South America, Asia, Africa, Indian Ocean Islands (Madagascar), Pacific Islands (Hawaii, New Zealand), Australia.

Discussion

Species 11 (1 in the flora).

Characters of Macrocoma include the rounded basal laminal cells, slender, irregularly branched stems, leaves erect-appressed when dry, cylindric capsules, peristome often reduced, and calyptra long conic-elliptic. There are often rhizoids present on the abaxial costa surface.

References

None.

Lower Taxa