Braunia

Bruch & Schimper

Bryol. Europ. 3: 159, plate 275. 1846

Etymology: For Alexander Carl Heinrich Braun, 1805 – 1877, Director of the Berlin Botanic Garden
Treatment appears in FNA Volume 28. Treatment on page 88. Mentioned on page 84, 89, 90, 642.
Plants large, deep yellow-green or reddish brown to blackish brown with age, not hoary distally. Stems with stoloniform-flagelliform branches present. Leaves ± loosely imbricate, ± longitudinally plicate, moderately to distinctly plicate-sulcate when dry, 1.5–2 mm; margins recurved proximally, recurved or plane in apex, erose-denticulate at apex; apex erect to somewhat secund and spreading when dry, erect- to wide-spreading when moist, acute to abruptly short-acuminate, sometimes apiculate in larger leaves, concolorous, strongly channeled, multipapillose; alar cells ± isodiametric, smooth to mostly 3-papillose, walls thick, or thinner near insertion, region concolorous or more strongly pigmented in 1 or 2 rows, sometimes gradually forming excavate auricle; mid basal laminal cells quadrate in 1 row, becoming long-rectangular to linear, papillae 4–8, in 1 row, walls ± thin to thick, not to moderately porose, region more deeply yellow to yellow-orange at insertion in 1 or 2 rows, rarely to 1/5 leaf length; medial cells 3–4(–6)-papillose over lumen, papillae simple, low and irregularly rounded, walls thin to thick, even or weakly to strongly porose-sinuate; distal cells chlorophyllose, similar to and concolorous with medial cells, less papillose; apical cells occasionally hyaline, or chlorophyllose with pellucid margins. Sexual condition autoicous or paroicous; perichaetial leaves similar to vegetative leaves, longer, 2–2.5(–3) mm, margins entire. Vaginula with paraphyses many, smooth, not extending onto developing calyptra. Seta dark reddish yellow, (5–)7–14(–25) mm, stout, extending beyond perichaetial leaves. Capsule exserted, brown, red at mouth, cylindric-fusiform when dry, ellipsoid or sometimes ovate (broadest at base) when moist, (1.9–)2–2.2 mm, irregularly striate-wrinkled to irregularly furrowed when dry, smooth when moist, mouth narrow; stomata phaneroporic; operculum conic, stoutly, bluntly, and obliquely medium- to long-rostrate. Calyptra cucullate, 2–4 mm, covering to below mid capsule, naked. Spores 18–23 µm, finely and evenly papillose.

Distribution

Nearly worldwide, mostly tropical and subtropical.

Discussion

Species 23 (2 in the flora).

Braunia is distinguished from the other two genera of the family in the flora area by the flagelliform-stoloniferous branches emerging laterally from the stem bases or from branch apices, bearing small, distantly spaced, squarrose-recurved, abruptly setaceous-acuminate leaves. The undersides of the mats are a tangle of wiry stolons. The stolons do not appear to be involved in the proliferation of the plant and may have more of a rhizoidal function, perhaps keeping the acrocarpous stem closer to the substrate. The essentially concolorous apices of the leaves are without whitened areas or filiform processes, although occasionally larger leaves will have several hyaline apical cells or chlorophyllose cells with pellucid margins; the apical cells are somewhat longer (3–4:1) in long-acuminate leaves. The leaves are plicate-undulate, like the ridges in a scallop shell. The capsules are not immersed as in Hedwigia, but distinctly exserted. The cells are multipapillose and the papillae are low, irregularly rounded rather than tuberculate or obviously branched. The perichaetial leaf apices are not pilose, with channeled acumina and a sharp apical cell.

Selected References

None.

Key

1 Leaf margins recurved proximally, plane distally; distal medial laminal cell walls straight or weakly sinuate; sexual condition autoicous. Braunia andrieuxii
1 Leaf margins recurved to near apex; distal medial laminal cell walls strongly sinuate; sexual condition paroicous. Braunia secunda