Cuspidatula Steph.
Cuspidatula Steph., Sp. Hepat. 2: 124. 1901.
Lectotype (fide Grolle, 1971a): Cuspidatula contracta (Reinw., Blume & Nees) Steph.
Plants rigid, prostrate, with ascending tips, light green to ± brown to purplish brown or reddish, nitid, medium-sized, to 2.5 mm broad. Branching sparse or rather common, irregular, the branches all or in part ventral-intercalary, evidently from ventral ends of lateral merophytes; Frullania -type branches also present in Cuspidatula contracta and at least at times in C. monodon. Stem wiry, with cortex in 1(2) layers of rigid, thick-walled cells; medullary cells larger, strongly thick-walled. Rhizoids frequent, scattered. Leaves widely spreading when moist, often dorsally ± connivent in drying, closely imbricate, asymmetrical to nearly symmetrical, ovate to ovate-lanceolate, unlobed, apices acute to short-acuminate or piliferous (occasionally obtuse to rounded in C. contracta), edentate; dorsal margin straight to arched, entire, the ventral arched, subcordate at the base, entire, exceptionally with a tooth. Cells in median sector mostly hexagonal to hexagonal-oblong, with strongly nodose trigones and conspicuous middle lamella; surface smooth or striate-papillose. Oil-bodies (C. monodon) 5–10 per cell, moderately botryoidal. Underleaves absent or vestigial, of 1–2 segments formed of 1–2 elongated cells, each ending in an ephemeral slime papilla. Asexual reproduction lacking (?or by fragmentation of leaf apices).
Dioecious. Androecia (data from Cuspidatula monodon) on leading shoots, rather inconspicuous, becoming intercalary; bracts somewhat smaller than leaves, the base ventricose, the distal sector tapering and similar in form to leaves; lobule margin involute, distinctly long-acuminate distally; antheridia 1 per bract, the stalk biseriate; paraphyllia lacking. Gynoecia terminal on leading leafy shoots or relatively short gynoecial innovations; bracts large, the insertion distinctly narrow, the bracts 2–4-lobed to 0.4–0.65, the lobes narrow, obtuse or long-acute to acuminate to caudate-piliferous, the lobe margins sparingly dentate-laciniate or entire, the lamina subentire or with a few small teeth or laciniae; bracteole free or narrowly connate on 1 side, smaller than bracts, oblong-lanceolate, undivided and distally acute or acuminate, on each side with a ciliiform to lobuliform process + a few small teeth, the bracteole at times bifid to ca. 0.5 in C. contracta. Perianths ovoid-cylindrical or oblong-obovate, terete basally, deeply plicate distally, the perianth moderately contracted toward the mouth; mouth irregularly lobulate, fringed with stiff, piliferous cilia.
Sporophyte known only for Cuspidatula monodon. Seta relatively short to rather long, of numerous, cells, the outer 1 (locally 2) rows of cells considerably smaller than the internal cells. Capsule ellipsoidal–narrowly ovoid, the wall 3–4-stratose, 23–30 µm thick; outer layer of cells notably small, subquadrate to short-rectangular, the walls uniformly hyaline, devoid of sheet-like thickenings, the radial longitudinal and transverse walls devoid of nodular thickenings or with at most 2, feebly pigmented, mostly low nodules; innermost cells irregularly long-rectangular (at times markedly so), with walls very thin, uniformly hyaline, devoid of sheet-like thickenings, with nodular thickenings that “trail off” onto the outer tangential wall as feebly pigmented, spur-like extensions, with opposing spurs at times approaching, but only exceptionally with complete semiannular bands.
Spores pale yellowish brown, 13.9–16.3 µm in diam. (including bacula), baculate, the bacula well-separated and truncate at the summit. Elaters somewhat tortuous, 5.8–7.7 µm wide, bispiral to tips, the spirals tightly wound, 1.9–2.4 µm wide.
Key
A genus with two species: Cuspidatula monodon, which is widely distributed in temperate Australasia, and C. contracta (Reinw., Blume & Nees) Steph. of New Guinea, Java, Sumatra, Philippines, Thailand, Amboina, Samoa, Tahiti, Fiji, Mauritius, Seychelles and Tanzania. Grolle (1971a) placed C. caledonica Steph. in the synonymy of Acrochila caledonica (Steph.) Inoue.
Kitagawa (1981) and Glenny (1998) treated Cuspidatula as a synonym of Jamesoniella; they are treated as discrete genera here, differing not only in sterile gametophytic characters, but in features of the androecium and sporophyte, as follows:
References: Hodgson (1946); Schuster (2002a).
