Plants small, green, yellow-green, or golden green. Stems gemmiform to evenly foliate, often in 2 or more clumps along stem, innovations and fertile stem leaves somewhat differentiated, innovations sometimes julaceous; rhizoids brown to red-brown, rarely red. Leaves imbricate, not folded along costa (folded along costa when dry in G. exile), ovate or ovate-lanceolate, sometimes triangular, concave; base not decurrent; margins entire distally, limbidium absent; costa percurrent to short-excurrent; inflated group of pinkish subalar cells absent; medial and distal laminal cells rhomboidal to elongate-hexagonal. Specialized asexual reproduction by leaf axil bulbils (and by rhizoidal tubers in G. exile). Sexual condition dioicous. Capsule erect or nutant, ovate, 1–3(–4) mm; hypophysis thick, abruptly tapered to seta, sometimes inflated and often rugose; peristome variable, well developed to reduced; endostome rarely adherent to exostome, basal membrane high to low, segments well developed or occasionally reduced, cilia long and appendiculate to short or sometimes absent.

Distribution

Nearly worldwide, including Antarctica.

Discussion

Species ca. 50 (7 in the flora).

Species of sect. Gemmabryum are strongly represented in temperate, subtropical, and tropical montane regions of the world, especially in seasonally temperate and Mediterranean climates. The plants are characterized by gemmiform stems with imbricate leaves, leaf axil bulbils, and variably developed peristomes with erect to nutant capsules. The leaves are erect when moist with stout costal awns. The capsule is perhaps the most distinctive feature, being short, ovate, and often with a thickened and rugose hypophysis.

Selected References

None.

Lower Taxa

Gemmabryum barnesii, Gemmabryum californicum, Gemmabryum coronatum, Gemmabryum dichotomum, Gemmabryum exile, Gemmabryum gemmiferum, Gemmabryum gemmilucens

Key

1	Specialized asexual reproduction by leaf axil bulbils and rhizoidal tubers; stems slender, stringlike when dry; leaves folded along costa when dry.	Gemmabryum exile
1	Specialized asexual reproduction by leaf axil bulbils, not by rhizoidal tubers; stems gemmiform to evenly foliate, not stringlike when dry; leaves not folded along costa	> 2
2	Capsules with hypophysis strongly thickened, inflated, strongly rugose; leaves ovate-lanceolate to triangular; margins revolute to mid leaf or beyond; bulbils 1 (or 2) per axil, primordia present.	Gemmabryum coronatum
2	Capsules with hypophysis somewhat thickened, not inflated, not or weakly rugose; leaves ovate to ovate-lanceolate or triangular; margins plane or revolute proximally; bulbils 1 to many per axil, primordia present or absent	> 3
3	Bulbils 250-750 µm, primordia arising from near base or mid bulbil, bulbils 1 (or 2) per axil.	Gemmabryum dichotomum
3	Bulbils (40-)50-450 µm, primordia arising from distal 1/3 of bulbil to tiered or absent, bulbils (1-)5-25+ per axil	> 4
4	Bulbils 150-450 µm, pyriform to conic or occasionally cylindric, primordia distinct	> 5
4	Bulbils (40-)50-200 µm, obconic to keyhole-shaped, or cylindric to spheric, primordia absent or very short and peglike	> 6
5	Bulbils 200-450 µm, primordia broad, obtuse, leaflike.	Gemmabryum barnesii
5	Bulbils 150-250 µm, primordia narrow, acute to peglike.	Gemmabryum gemmiferum
6	Plants yellow-green to golden; leaves ovate to triangular; bulbils (40-)50- 70 µm, keyhole-shaped to obconic.	Gemmabryum californicum
6	Plants green or yellow-green; leaves ovate; bulbils 100-200 µm, cylindric to spheric.	Gemmabryum gemmilucens