Keys modified from Muñoz (1999).
1. Leaves strongly plicate on both sides of costa … 2.
1. Leaves not plicate or only weakly so … 3.
2. Setae curved; capsules asymmetric and ventricose at base, gymnostomous; calyptrae mitrate, not exceeding further down than the capsule mouth, not plicate … G. trinervis
2. Setae straight; capsules symmetric with the seta centrally placed at base, peristome present; calyptrae campanulate, extending below capsule mouth, plicate … see Coscinodon
3. Capsules asymmetric and ventricose at base; seta eccentrically attached to the capsule, curved, shorter than capsule … G. anodon
3. Capsules symmetric OR specimens sterile; seta centrally attached to the capsule and, if curved, longer than the capsule… 4.
4. Proximal marginal leaf cells with all walls similar, thin-walled … 5.
4. Proximal marginal leaf cells with transverse walls thicker than longitudinal walls … 7.
5. Margins plane throughout or incurved above, no trace of recurvation … G. donniana
5. Margins recurved, at least on one side for part of its length … 6.
6. Longest hair-points longer than 0.3 mm, most of the leaves piliferous; autoicous, made buds small and lateral, hidden just below perichaetia; setae curved (sporophytes generally present) … G. fuscolutea
6. Longest hair-point to 0.3 mm long, most of the leaves muticous; dioicous, male buds terminal; setae straight … G. elongata
7. All leaves constantly muticous (without a point or awn) … G. atrata
7. At least perichaetial leaves with a trace of a hair-point … 8.
8. Margins plane or incurved … 9.
8. Margins recurved, at least on one side for part of its length … 11.
9. Distal half of lamina unistratose, only 1 or 2 marginal rows 2-stratose … G. pseudoanodon
9. Distal half of lamina 2 to 3(4)-stratose … 10.
10. Costae semicircular (cross-section), scarcely prominent on dorsal surface, occasionally the same thickness as lamina, scarcely differentiated … G. tetrestina
10. Costae elliptical (cross-section), prominent on dorsal surface … G. reflexidens
11. Ventral layer of costae 2-6 cells wide, cross-section of costae reniform … G. longirostris (see also G. herzogii)
11. Ventral layer of costae 2 cells wide, cross-section of costae semicircular, never reniform … 12.
12. Laminar cells bulging (cross-section) … G. reflexidens
12. Laminar cells not bulging (cross-section) … 13.
13. Lamina mostly unistratose in upper 2/3, with bistratose margins and/or occasional and small 2-stratose patches … 14.
13. Lamina 2-3(4)-stratose for most of upper 2/3 … 16.
14. Leaf section forming an angle less than 30º, parallel at the junction with the costa, furrow very narrow … G. navicularis
14. Leaf section forming an angle greater than 45º, divergent at base, furrow more open … 15.
15. Propagula sessile on lamina, seldom on the costa, not stalk remaining after propagula liberation, which causes leaf destruction; lamina bistratose at margins and in streaks; plants less than 3 cm; spores minutely granulose, apparently smooth under light microscope … G. trichophylla
15. Propagula on stalks at dorsal base of costa, the stalk 1(2) cells long remaining attached to the costa after propagula liberation, which does not affect the leaf; lamina unistratose except sometimes 2-stratose in 1-2 rows at margin; plants to 8 cm; spores coarsely and distinctly granulose under compound microscope … G. austrofunalis
16. Leaf section forming an angle less than 30º, parallel at the junction with the costa, furrow very narrow … G. navicularis
16. Leaf section forming an angle greater than 50º, divergent at base, furrow open … 17.
17. Leaves appressed, straight; setae straight; capsules immersed; autoicous … G. molesta
17. Leaves flexuous; setae curved; capsules exserted; dioicous … G. bicolor