Grimmia elongata Kaulf.

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 : 208-210

3. Grimmia elongata Kaulf.

in J. Sturm, Deutschl. Fl. II(15): tab. 14. 1816

( Fig. 5 ).

Lectotypus (designated by Geissler & Maier, 1995: 500): AuStriA: “ In Styria alpibus ”, s.d., Kaulfuss s.n. ( B!; isolecto-: BM [ BM000867904 ] image seen, G [ G00052982 ]!).

Gametophyte. Dioicous. Female: innermost perichaetial leaf 2.8-3.5 mm long, sheathing up to mid-leaf, from ovate, elongated base constricted above mid-leaf to narrow upper part, leaf base hyaline, some rows of hyaline cells vanishing above broadest part, costa stout, excurrent into short, weakly denticulate hairpoint; male: plants in separate cushions, perigonia as small buds on short stalks in leaf axils, several per stem, innermost perigonial leaf 0.7 mm, sheathing, ovate, strongly keeled, apex muticous, acute, hyaline up to broadest part, costa percurrent, paraphyses few. Growth form: cushion dense, disintegrating easily, young shoots originating from older stems, leaflets muticous, appressed to stem, plants somewhat radiculose at base, erect, branched, stem up to 40 mm high, thin, central strand poorly developed, occasionally lacking. Leaves 1.2-1.8 mm long, imbricate, in short-leaved form appressed to stem, in long-leaved form slightly twisted and loosely disposed on stem when dry, bending backwards when moistened, leaf base appressed to stem, laminal part patent, from narrow oval leaf base elongate-lanceolate, straight or somewhat falcate, on one side above broadest part markedly narrowed to apical part, thus forming shoulder, on nearly straight side margin recurved from leaf base up to mid-leaf, short leaves muticous, slightly cucullate, longer leaves apiculate, hair-point short, smoothly denticulate; leaf form in situ, at insertion and leaf base concave, at transitional part lamina spreading from costa, lower laminal part keeled, upper part narrowly so, margin at one side from insertion up to mid-leaf recurved; basal cells elongaterectangular, walls smooth except some cell rows between margin and paracostal cells with faintly nodulose walls, at margin 3-4 rows narrowly elongate-rectangular, hyaline, thin-walled cells, gradually vanishing, outermost row ascending up to above broadest part of leaf, cells becoming short-rectangular to quadrate, walls more or less sinuose, in upper laminal part oval to isodiametric, lumina rounded, walls thickened; seen in transverse section, leaf base unistratose, lamina in places or entirely bistratose, margin unistratose at leaf base, in laminal part some cell rows bi- or tristratose. Costa, seen on dorsal side, weak at leaf base, stout in laminal part, reaching apex, in upper part dorsal cells similar in shape to proximate lamina cells, seen in transverse section, costa on dorsal side rounded at insertion and leaf base, occasionally prominent in laminal part, in rare cases faintly mammillose, on ventral side at insertion and leaf base widely channelled, in middle part of lamina narrowly so, keeled in apical part, at insertion and leaf base 4 guide cells, in laminal part 2 guide cells, at insertion and leaf base substereids, in upper part cells rounded, homogeneous, hydroids from insertion up to mid-leaf.

Sporophyte. Seta erect, inclined or arcuate, 2.0-3.5 mm long, vaginula 0.8-1.2 mm long, cylindrical, ochrea small. Capsule emergent, erect, inclined or cernuous, ovoid or obloid, smooth, exothecial cells of variable shape, isodiametrically or elongated penta- and hexagonal, walls curvilinear, slightly thickened, stomata more or less numerous at capsule base, annulus of 2-3 rows of cells detaching singly, the lumen narrow, round. Calyptra mitrate-cucullate. Operculum conical, blunt, margin smooth of two rows of rounded cells, in conical part ovate, walls thickened. Peristome teeth erect or recurved when dry, broad at base, rarely slit or perforate, inner and upper outer side covered with rough, rounded and sharp papillae, lower outer side sparingly ornamented with fine papillae, trabeculae thin, scarcely protruding in lower part, conspicuously protruding in upper part. Spores 12-16 µm, granulose.

Diagnostic characters. – Gametophyte. Leaves with margin recurved on one side, with several marginal rows of elongate-rectangular, thin-walled, hyaline cells, reaching from insertion to above the broadest part of leaf, vanishing gradually, outer row ending in short-rectangular to quadrate cells. Costa, in upper part, dorsal cells similar in shape to proximate lamina cells.

Distribution, habitat and ecology. – Grimmia elongata is disjunctively distributed in mountains of the northern hemisphere with sporadic southwards extensions through the Andes, and central, eastern, and southern Africa.

In South Africa and Lesotho G. elongata ( Fig. 1 C) is disjunctively distributed between a few high altitude (2,200-3,250 m) localities in the Drakensberg and a single high summit (the Matroosberg) in the SW Cape. Known from basalt as well as from hard, nutrient-poor, quartzitic sandstones.

Notes. – All specimens seen from the study area are sterile. In this species the stratosity of the lamina and margin is variable. The leaf base is unistratose, with the lamina partly bistratose, to a varied extent. The margins may also be tristratose.

Selected specimens examined. – South AfriCA. Prov. Western Cape: Ceres - De Doorns Area , Matroosberg NR , Summit , 2200 m, 33°23’05”S 19°40’01”E, 9.XII.2003, Hedderson 15448, 15449; ibid. loc., Hedderson 15455 ( BOL). leSotho: Butha-Buthe Distr., 20 km SE of New Oxbow Lodge on the road to Mokhotlong, 3250 m, 28°49’S 28°43’E, 15.IV.1994, Matcham 1094a (herb. Matcham).

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. 5. – Grimmia elongata Kaulf. A. Transverse section of stem, with central strand; B. Transverse section of stem, without central strand; C, D. Leaves; E. Outlines of transverse section of leaf; F. Cells in leaf base and transitional part; G. Dorsal cells of costa in apical part; H. Transverse section of leaf. [A, B, E: Hedderson 15449, BOL; C, F: Hedderson 15448, BOL; D, H: Hedderson 15455, BOL; G: Matcham 1094 a, herb. Matcham]