Grimmia, Hedw.

Eva Maier, Michelle J. Price & Terry A. Hedderson, 2017, A revision of Grimmia (Grimmiaceae) from South Africa and Lesotho, Candollea 72 (1), pp. 199-230 : 203-204

publication ID	https://doi.org/ 10.15553/c2017v721a12
DOI	https://doi.org/10.5281/zenodo.5722004
persistent identifier	https://treatment.plazi.org/id/03AC87ED-6D5E-FF9B-FCA6-E30625A1F888
treatment provided by	Plazi
scientific name	Grimmia
status

Treatment

Key to Grimmia View in CoL species from South Africa and Lesotho

As plants are often collected without sporophytes, and when present the sporophytes are often in poor condition, we have utilised only gametophytic characters. (Plants should be examined in the wet state).

1. Cross section of costa at insertion with 7 or more guide cells (see Fig. 8 View Fig. 8 G, H), in lamina with 2 guide cells sunken into narrow channel, their adaxial walls strongly thickened, at insertion with a small median band of substereids, interrupted by 3 groups or 1 large central group of hydroids that vanish in the apical part .............................. 6. G. laevigata View in CoL

1a. Costa cross section at insertion with fewer than 7 guide cells ............................................................................... 2

2. Costa cross section at insertion with 6 guide cells (see Fig. 9 View Fig. 9 F); in lower lamina costa unevenly rounded and somewhat angulate as seen in surface view, indistinct in apical part of leaf; basal cells with transverse walls markedly thinner than longitudinal ...... 7. G. longirostris View in CoL

2a. Costa at insertion with 4 guide cells or with 4 guide cells of which the outer two are contiguous with the basal cells .............................................................................. 3

3. Costa at insertion with 4 guide cells, outer guide cells non-contiguous with the laminal cells ......................... 4

3a. Costa at insertion with 4 guide cells, the two outer ones contiguous with the laminal cells (see Fig. 3F, G View Fig. 3 ; 6G, H) ....................................................................... 12

4. Basal paracostal cells (excluding marginal cells) nodulose....................................................................... 5

4a. Basal paracostal cells (including marginal cells) smooth ..................................................................................... 8

5. Transverse section of leaf base not concave, leaf base with a marginal border (see Fig. 5 View Fig. 5 F) of narrowly elongaterectangular, hyaline, thin walled cells in 3-4 rows, gradually transitioning to short-rectangular to quadrate cells but with outermost row ascending to above broadest part of leaf; margin recurved on one side from insertion to mid-leaf (see Fig. 5 View Fig. 5 C, D); lamina unistratose (see Fig. 5 View Fig. 5 H), rarely with bistratose patches..... 3. G. elongata View in CoL

5a. Transverse section of leaf base concave, plants otherwise ... 6

6. Transverse section of leaf above broadest part broadly keeled (see Fig. 7 View Fig. 7 I), unistratose at insertion and leaf base, partially bistratose in laminal part, bistratose in apex; margin with several rows of bistratose cells; costa in transverse section (see Fig. 7 View Fig. 7 I), with or without hydroids, cells in transitional part of leaf with walls smooth or sinuose (see Fig. 7 View Fig. 7 H) .................................. 5. G. kidderi View in CoL

6a. Transverse section of leaf above broadest part not broadly keeled; plants lacking the above combination of characters ............................................................................... 7

7. Transverse section of costa at insertion with dorsal cell walls slightly bulging (see Fig. 13 View Fig J, K), below mid-leaf with 2 narrowly elliptical median guide cells arranged obliquely to leaf axis; marginal cells partly bi-tristratose in 1-3 rows above the leaf base; laminal cells in transitional zone elongate-rectangular (see Fig. 13 View Fig G, I), walls sinuose ................................................... 11. G. pygmaea View in CoL

7a. Transverse section of costa at insertion with dorsal cell walls bulging (see Fig. 11 View Fig H), the guide cells rounded, arranged horizontally; margin unistratose or at most bistratose in 1 cell row on one side in apex; lamina cells in transitional zone short-rectangular or isodiametric with walls smooth or slightly sinuose (see Fig. 11 View Fig G) .............. .............................................................. 9. G. orbicularis View in CoL

8. Cells in leaf base elongate-rectangular......................... 9

8a. Cells in leaf base short-rectangular............................ 11

9. Basal cells of upper stem leaves elongate-rectangular (see Fig. 14 View Fig. 14 D), with thickened transverse walls throughout; lower stem leaves with inner elongate rectangular and evenly thickened walls (see Fig. 14 View Fig. 14 E), but with 2-3 marginal rows short-rectangular to quadrate cells and with thickened transverse walls; margin (transverse section) (see Fig. 14 View Fig. 14 C) plane or occasionally recurved on one side from insertion to transitional zone (see Fig. 14 View Fig. 14 F) ................................................ 12. G. sessitana View in CoL

9a. Cells of leaf base elongate-rectangular, hyaline with cell walls evenly thin, margins plane................................. 10

10. Costa in transverse section markedly stout in the lamina (see Fig. 15 View Fig. 15 H), indistinct at apex, without hydroids but with abundant stereids; leaf forming a v-shape in crosssection in upper leaf................................ 13. G. tortuosa View in CoL

10a. Costa in transverse section not markedly stout in laminal part, distinct at apex; transverse section with hydroids, stereids absent but substereids usually present; leaf section otherwise in upper leaf............... 2. G. donniana View in CoL

11. Leaves abruptly lanceolate from ovate base (see Fig. 10 View Fig. 10 B), thus with distinct shoulders, keeled (transverse section) from mid-leaf to apex (see Fig. 10 View Fig. 10 H, I); in transverse section margin gradually incurved from base to apex (see Fig. 10 View Fig. 10 D, I), lamina bistratose (see Fig. 10 View Fig. 10 H, I), costa prominent above leaf base....................... 8. G. montana View in CoL

11a. Leaves broad-lanceolate or lanceolate from a short, ovate leaf base, keeled from leaf base to apex (transverse section) (see Fig. 12 View Fig. 12 H, I), thus lacking distinct shoulders, in transverse section margin recurved on one side to above midleaf (see Fig. 12 View Fig. 12 C), rarely on both sides and then with one side recurved only at middle of leaf; lamina unistratose from insertion to apex (see Fig. 12 View Fig. 12 H), usually with marginal 1-2 cell rows that are bi- tristratose, occasionally only on one side and rarely unistratose ( Fig. 12 View Fig. 12 I), costa prominent throughout ..................................... 10. G. pulvinata View in CoL

12. Costa in dorsal view strikingly small and thin from insertion to broadest part of leaf ( Fig. 3B View Fig. 3 ), becoming stout and prominent towards the apex; transverse sections of costa in the upper stout portion with a group of hydroids (see Fig. 3F, G View Fig. 3 ); leaf bases auriculate, decurrent (see Fig. 3D View Fig. 3 ) ................................................ 1. G. consobrina View in CoL

12a. Costa in dorsal view weak at insertion and leaf base but enlarged throughout laminal part ( Fig. 6 View Fig. 6 B); above the broadest part of leaf the 2 median guide cells become narrowly elliptical and obliquely oriented to leaf axis (see Fig. 6 View Fig. 6 G, H); hydroids sometimes present in leaf base (see Fig. 6 View Fig. 6 H); leaf bases neither auriculate nor decurrent ........................................................ 4. G. fuscolutea View in CoL