Grimmia kidderi James

5. Grimmia kidderi James

in Bull. Torrey Bot. Club 6: 54. 1875

(Fig. 7).

Lectotypus (designated by Muñoz, 1999: 143): frAnCe. French Southern and Antarctic Territories: Kerguelen Island, 1874, Kidder s.n. (FH!; isolecto-: FH!).

Gametophyte. Dioicous. Female: innermost perichaetial leaf up to 4 mm long, slightly sheathing up to shoulder at midleaf, costa stout, excurrent to scarcely denticulate hair-point; male: perigonia not seen. Growth form: cushion dense, adherent to substrate with grayish, in wet state hyaline, rhizoids, interwoven with young shoots, originating from older stem parts, leaflets scale-like, concave, muticous or with a hyaline end cell, in dry state firmly appressed to stem, apices spreading, producing bristly aspect, plants erect, sparsely branched, stems up to 10 mm high, central strand small. Leaves from lower part of stem 0.3-0.5 mm long, concave, muticous, becoming progressively longer, up to 1.7 mm long, loosely arranged to stem, erect when dry, moving weakly when moistened, erect or erecto-patent when wet, from ovate leaf base narrowly lanceolate, tapering to obtuse apex, muticous or with hairpoint of different length, bluntly denticulate; leaf form in situ, from insertion up to apical part concave or above broadest part of leaf widely keeled, in apical part keeled, margins plane throughout; basal paracostal cells elongate-rectangular, thickwalled, more or less nodulose, towards margin rectangular, becoming short-rectangular to quadrate in transitional part, walls smooth, thickened, especially the transverse walls, cells in laminal part isodiametric, lumina rounded; seen in transverse section, leaf base unistratose, in lower laminal part uni- to bistratose, apical part bistratose, occasionally with tristratose marginal cell rows. Costa, seen on dorsal side, of even width throughout, not reaching apex, seen in transverse section, costa rounded, on ventral side widely channelled, in upper part of leaf channelled or narrowly channelled, at insertion and leaf base 4 guide cells, in laminal part 2, with hydroids.

Sporophyte. Seta slightly curved, 1.2 mm long, vaginula 0.6 mm long, with ochrea. Capsule hidden in the leaves, ovoid, smooth, after spore release enlarged at orifice, exothecial cells elongated, walls thick, in surface view strongly thickened, stomata rare in capsule base, annulus disintegrating in fragments. Calyptra not seen. Operculum conical, beak long, oblique, smooth at margin, all cells rounded, thick-walled. Peristome teeth reflexed in dry state, entire, on inner and upper outer side densely ornamented with sharp papillae, the lowest outer plates finely and sparingly papillose, trabeculae close together, small, scarcely protruding. Spores 10-13 µm, finely granulose.

Diagnostic characters. – Gametophyte. Perichaetial leaves markedly longer than vegetative leaves; leaves narrowly lanceolate, concave nearly throughout, margins plane. Sporophyte. Capsule immersed.

Distribution, habitat and ecology. – Grimmia kidderi is a southern-temperate species recorded from Argentina, Chile, the Kerguelen Islands, Ascension Island, Tristan da Cunha and South Africa.

In South Africa and Lesotho G. kidderi is rare and currently known only from two localities on the high summits of the northern and middle Cederberg from 1,150-1,870m, as well as from a single locality on the Great Escarpment of the Eastern Cape Province (Fig. 1 E). This species is found in fynbos with outcropping sandstone, and on sandstone cliffs and seasonally wet rock slabs. Whilst apparently genuinely rare in the west, it may be under-collected in the eastern part of its range.

Notes. – The four specimens seen were sterile. The description of the sporophyte herein is based on Skottsberg 371 (H-BR) from the Patagonian region of Argentina (Maier, 2010: 180). The stratosity of the lamina in this species is variable. Some collections of G. kidderi from the study area have bulging cells with hyaline outer walls on the dorsal surface of the leaves. This phenomenon is not restricted to this species and seems to be due to harsh conditions under which the plants are growing.

Selected specimens examined. – South AfriCA. Prov. Western Cape: Cederberg. Zuurvlakte, 1150 m, 32°36’32”S 19°12’12”E”, 27.II.2000, Hedderson 13081 (BOL); Citrusdal Region, Cederberg State Forest, E side of Langberg, and slopes of Shadow Peak, 1550-1870 m, 32°23’20”S 19°10’25”E, 17.II.2001, Hedderson 13724 (BOL); ibid. loc., Hedderson 13744 (BOL).