Entosthodon zygolimbatus N. Wilding, 2017

Wilding, Nicholas, 2017, Three new species of Entosthodon Schwägr. (Bryopsida, Funariaceae) from sub-Saharan Africa, Phytotaxa 312 (1), pp. 103-110 : 107-108

Entosthodon zygolimbatus N. Wilding , sp. nov. ( Fig. 3 )

Diagnosis:—Differing from all other species of the genus Entosthodon by its combination of zygomorphic capsules, strongly limbate leaf margins and coarsely verrucate-lirate spores.

Type:— SOUTH AFRICA. Mpumalanga: Dullstroom, 14 km north on Verlorenvallei farm, 2010 m, 14 October 1980, B. K. Drews 19 ( PRE, holotype!; isotype MO!) .

Plants medium, light-green. Stems reddish-brown, to 5 mm high, branching multiple times by sub-perigonial innovation; in cross-section with 1–2 layers of thick-walled cortical cells, a hyalodermis and a central strand; rhizoids cerise. Leaves erect-spreading, contorted when dry, oblong-obovate to spathulate, 2.2–3 × 1.1–1.5 mm, plane to slightly concave, short-acuminate to apiculate, entire to weakly serrate in upper ⅓, arista absent; cells of upper lamina rectangular or rhomboidal to oblong-hexagonal, 45–63 × 25–38 μm; basal cells 112–225 × 25–38 μm; marginal cells frequently narrower, thicker-walled, forming a border 1–2 cells wide; costae ending below apex.

Polyoicous. Setae 8–16 mm long, straight to slightly curved, reddish-brown. Capsules erect to inclined, weakly gibbous, zygomorphic, oblong-pyriform, 1.5–2.1 × 0.5–0.8 mm, weakly constricted below mouth when dry, yellow to reddish-brown at maturity, with a well differentiated neck ca. ½ total length of capsule; mouth slightly oblique, ca. ¾ diameter of capsule; exothecial cells 32–53 × 15–23 μm, in cross-section with thick, strongly cuneate anticlinal walls, 4–5 rows of oblate cells at mouth. Opercula not seen. Peristome single (possibly double, see below); exostome teeth straight, regular in shape, orange, to 230 μm high, ca. 60 μm wide at base, striate, trabeculate. Spores 25–28 μm, tetrahedral, coarsely verrucate-lirate. Calyptrae not seen.

Additional specimens examined: TANZANIA. Morogoro Districtrict: South-Uluguru Mts., in gorge of Mgeta River Falls at East edge of Lukwangule Plateau, 9 June 1988, T. Pócs, R. Ochyra & H. Bednarek‒Ochyra 88108/ M ( BOL, E, EGR, MO, PRE, S).

Etymology: The species epithet is derived from the presence of zygomorphic capsules and limbate leaf margins.

Note: The strongly limbate, dentate leaves and zygomorphic, gibbous capsules clearly distinguish E. zygolimbatus from other African species. The peristome morphology of this species, in particular exostome shape and ornamentation, and whether or not an endostome is present, remains slightly obscure because of a lack of well-preserved capsules in the only two known collections. The species is quite possibly a close relative of the Andean-Australasian species E. radians Hedwig (1801: 73) Müller (1848: 122) . The two species share a similar overall morphology, of which the only major difference is in the ornamentation of their spores (baculate-insulate in E. radians vs. coarsely verrucate-lirate in E. zygolimbatus ), the two species also share similar high elevation habitats. E. zygolimbatus can also be confused with E. curvipes Müller (1845: 697) Müller (1848: 126) , however, the latter differs in having leaves with a weaker border of 1–2 cells wide, significantly longer peristome teeth (to 450 μm) and highly-thickened exothecial cell walls.

Habitat and distribution: The species is known from only two localities, one in South Africa and one in Tanzania. Entosthodon zygolimbatus is recorded from elevations between 2000 m and 2400 m in tropical and subtropical zones.

Figures

FIGURE 3. Entosthodon zygolimbatus. 1. Habit, dry; 2–4. Leaves; 5. Leaf apex; 6. Leaf cross-section; 7. Capsule mouth & peristome (teeth missing in image); 8. Spores. All from: T. Pócs, R. Ochyra & H. Bednarek‒Ochyra 88108/M, BOL. Scale bars: A (2–4) = 500 μm; B (5, 7) = 100 μm; C (1) = 1 mm; D (6) = 100 μm; E (8) = 50 μm.