Grimmia fuscolutea Hook.

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 : 210-211

4. Grimmia fuscolutea Hook.

, Musci. Exot. 1: 63. 1818

( Fig. 6 ).

Lectotypus (designated by Muñoz & Pando, 2000: 31): South AmeriCA: sine loc., s.d., Humboldt 50 [H 2673] ( BM [ BM000670173 ]!; isolecto-: BM000535435 !).

5 Grimmia sanii Greven in Bryologist 99: 429. 1996.

Typus: South AfriCA. Prov. Natal: Crows’ Nest. Mount aux Sources , 3048 m, VII.1947, Schelpe 2115 (holo-: PRE!; iso-: BOL! [3 packets filed under G. pulvinata (Hedw.) Sm. ]), synonymized by Muñoz (1999: 138).

Gametophyte. Monoicous. Female: innermost perichaetial leaf up to 3.8 mm long, sheathing in lower part, shape and cell pattern as in stem leaves, lower third hyaline, costa excurrent to elongated, denticulate, slightly decurrent hair-point; male: perigonia below perichaetium in leaf axil as bud on short stalk, innermost perigonial leaf 0.8 mm long, slightly sheathing, ovate, apex rounded or obtuse, hyaline up to 2/3 of leaf length, costa percurrent, paraphyses short, few. Growth form: cushion compact, adherent to substrate with rhizoids, from where the young shoots originate, leaflets patent, muticous, apex acute, plants erect, branched in upper part, rhizoids in leaf axils, stems up to 15 mm high, central strand well-developed. Leaves up to 1.5 mm long, crowded, imbricate, appressed to stem and somewhat contorted when dry, slowly spreading when moistened, erecto-patent and stiff when wet, from ovate base lanceolate or broad-lanceolate, slightly asymmetric, tapering to acuminate apex, hair-point of different length, smoothly denticulate; leaf form in situ, concave at leaf base, with a more or less expressed plica near the costa on one side, and another one in the middle of the lamina on the other side, keeled in lower laminal part, narrowly keeled in upper laminal part, margin recurved or revolute on larger side from leaf base up to laminal part, on other side more or less recurved, in upper part both sides plane; all basal cells elongated, walls smooth or nodulose, thin- or thick-walled, at margin two or three rows of hyaline cells, vanishing above leaf base, in transitional part and lower half of lamina cells rectangular, walls strongly or weakly sinuose, arranged as strict, perpendicular rows parallel to costa, upper cells short-rectangular, walls sinuose; seen in transverse section, leaf base unistratose, laminal part unistratose, bistratose in places, apical part partly bistratose, in laminal part one or two marginal cell rows bistratose, dorsal and ventral exterior cell walls scarcely or distinctly bulging or occasionally with joint thickenings. Costa, seen on dorsal side, at insertion and leaf base weak, enlarged in laminal part, excurrent to hairpoint, in muticous leaves vanishing below apex, seen in transverse section, costa on dorsal side at insertion and in leaf base rounded, in laminal part prominent, mammillose, on ventral side channelled, narrowly so in upper part, at insertion and leaf base 4 ventral cells, 2 median ones are guide cells, the 2 outer ones belong partly to basal paracostal cells, above broadest part of leaf reduced to 2 narrow elliptical guide cells, obliquely arranged to leaf axis, at insertion and leaf base a median group of hydroids or stereids, transformed to substereids in upper laminal part, vanishing in apical part.

Sporophyte. Seta arcuate, up to 2.5 mm long, vaginula 0.8 mm long, cylindrical, ochrea small. Capsule emergent, horizontal or pendent, ovoid, of various size, with apophysial part, plicate, in mature state nearly smooth, constricted below orifice, exothecial cells irregularly elongated, pentagonal, walls curvilinear, thin or thick (depending on focussing), stomata large, numerous at apophysis, annulus of 3-4 cell rows, detaching as spirals. Calyptra mitrate, lobed, covering operculum. Operculum conical, beak obtuse of variable length, margin smooth, some marginal rows of rounded or short-rectangular cells, in conical part cells rounded-rectangular, thinwalled. Peristome teeth spreading when dry, lanceolate, broad at base, perforated longitudinally or slit into two branches, at dehiscence joined at base, separating subsequently, lower dorsal side covered with prickly papillae, upper dorsal and ventral sides densely covered with pointed papillae, trabeculae thin, in upper part distant, scarcely protruding. Spores 10-12 µm, granulose.

Diagnostic characters. – Gametophyte. Leaves basally plicate on one side near the costa ( Fig. 6 C), basal cells elongated ( Fig. 6 D). In transverse section, costa with small, elliptical guide cells oriented obliquely to leaf axis in laminal part.

Distribution, habitat and ecology. – Disjunctively distributed, Grimmia fuscolutea is known in the northern hemisphere from the European Alps, and from scattered localities in the Himalaya (India, Nepal) and from Japan. In the southern hemisphere this species occurs along the South American Andes as far north as Mexico and in Africa from South Africa and Reunion Island.

In South Africa and Lesotho ( Fig. 1 D), G. fuscolutea occurs in mid- to high-altitude sites (730-3,370 m) from the northern Cederberg, south through the Cape Fold Mountains, and eastward along the Great Escarpment (where it is known from only three localities), to the Drakensberg. It grows on hard, quartzitic sandstones, basalt or dolerite in fynbos and grassland habitats.

Notes. – A total of 32 specimens were seen, 17 with sporophytes but only one with a capsule in a suitable state for examination.

Selected specimens examined. – South AfriCA. Prov. Natal: Underberg, Distr. Sani Pass , 8.XI.1973, Hilliard & Burtt 7115 ( BOL). Orange Free State Prov. Witzieshoek, base of Sentinel , 2740 m, Schelpe 7682 ( BOL).

Figures

Fig. 1. – Species richness (A) and geographic distribution (B-F) of Grimmia Hedw. species in South Africa and Lesotho. A. Distribution of species richness in the genus Grimmia Hedw. at the Quarter-Degree Square (QDS) scale; B. Grimmia consobrina Müll. Hal.; C. Grimmia donniana Sm. (stars) and G. elongata Kaulf. (circles); D. Grimmia fuscolutea Hook.; E. Grimmia kidderi James; F. Grimmia laevigata (Brid.) Brid.

Fig. 6. – Grimmia fuscolutea Hook. A. Transverse section of stem; B. Leaf; C. Outlines of transverse sections of leaf; D. Cells in leaf base; E. Cells in transitional part; F, G, H. Transverse sections of leaves. [A-E, H: Hilliard & Burtt 7115, BOL; F: Schelpe 7682, BOL; G: Schelpe 2115, PRE]