Dicranodontium uncinatum Jaeger 1880

Type of Dicranodontium blindioides var. robustum matches the concept of D. uncinatum very well and its distribution range falls in line with that of D. blindioides, which is also a synonym of the latter species.

Sporophytes are not known or reported for North American plants of Dicranodontium uncinatum. H. C. Gangulee (1971) reported them for eastern India where the plants fruited in October with capsules containing spores 16-17 µm. The largest North American species of the genus, D. uncinatum has stems usually 2-8 cm, sometimes up to 14 cm. It is easily recognized by its hook-shaped leaves. It is often confused with D. denudatum, which has shorter leaves, mostly less than 8 mm, auriculate, with an indistinct costa and alar cells that are narrowly rectangular and usually reddish. In D. uncinatum the cells distal to the alar region and adjacent to the costa are broadly rectangular and hyaline.

Plants coarse, fairly robust, up to 7(–10) cm high, yellowish green to pale brownish, somewhat silky, in loose or dense tufts. Stems erect to flexuose or curved, simple or sparsely branched; central strand present. Leaves up to 8(–12) mm long, strongly falcate-secund at upper stems, scarcely altered when dry, lanceolate, rather abruptly narrowed from an oblong-ovate, sheathing base to a long, subulate to semi-canaliculate acumen, sharply pointed at the apex; margins somewhat involute, entire below, serrulate near the apex; costa yellowish to reddish brown, occupying ¼ – 1/3 the leaf base width, excurrent in a short awn, slightly longitudinally furrowed and serrulate at back above; upper cells linear, thick-walled, distinctly projecting at the upper ends; lower cells rectangular, 38–70 µm × 15–20 µm, thick-walled and porose, pale yellowish, forming 5–7 rows of linear cells at the margins; alar cells inflated, thin-walled, forming well marked auricles, sometimes fragile, hyaline or reddish brown. Dioicous. Setae 8–12 mm long, yellowish, strongly flexuose when dry, cygneous when moist; capsules cylindric, brownish, ca. 2 mm × 0.7 mm, exothecial cells rectangular, slightly thick-walled; peristome teeth divided nearly to the base, reddish brown, vertically striate below; papillose at the tips. Spores 16–17 µm in diameter, pale yellowish.

Plants brown proximally, yellowish green or yellowish brown to dark green distally, glossy, in loose to dense tufts. Stems 2-8(-14) cm, radiculose proximally with reddish brown rhizoids. Leaves falcate-secund, especially at stem apices, sometimes erect and flexuose, spreading at ca. 30º when wet, 5-10 mm, occasionally deciduous, somewhat abruptly narrowed from an ovate to oblong base into a setaceous subula, subtubulose proximally, channeled distally, margins entire proximally, serrate to serrulate near apex, apex acute; costa distinct, occupying ca. ¹/5-¹/3 of leaf base; cells thick-walled and pitted only in leaf base, distal cells linear, 24-56 × 5-9 µm, basal cells broadly rectangular, hyaline, ca. 16 µm wide, alar cells not forming auricles, thin-walled, hyaline. Seta 8-11 mm, erect-sinuose to cygneous. Capsule 1-1.8 mm; operculum straight, ca. 1 mm. Spores 16-17 µm.

Distribution: China, Bhutan, Nepal, India, Sri Lanka, Myanmar, Thailand, Vietnam, Indonesia, Malaysia, the Philippines, Japan, Europe, and North America.

Habitat: on soil, rocks, grasslands, or rotten wood and bases of trees.

Dicranum uncinatum (Harv.) C. Müll., Syn. Musc. Frond. 1: 404. 1848, hom. illeg. Dicranodontium blindioides (Besch.) Broth., Nat. Pflanzenfam. 1(3): 336. 1901. Dicranum blindioides Besch., Rev. Bryol. 18: 88. 1891. Type. China: Yunnan, Lopin-chan (Lan-Kong), Delavay 4815 (holotype H). Synonymized by Frahm (1997). Dicranodontium blindioides var. robustum Broth. in Handel Mazzetti, Symb. Sin. 4: 20. 1929. syn. nov. Type. China: Yunnan, 27o 53´N, alt. 2130 m, Handel-Mazzetti 9333 (holotype H). Dicranodontium circinatum (Milde) Schimp., Syn. Musc. (ed. 2): 100. 1876. Dicranum longirostre var. circinatum Milde, Bot. Zeit 28: 417. 1870. Dicranodontium fleischerianum Schultze-Motel, Taxon 12: 127. 1963. Dicranodontium fleischerianum var. clemensiae (Bartr.) Schultze-Motel, Taxon 12: 127. 1963. Dicranodontium nitidum var. clemensiae Bartr., Philippine J. Sci. 61: 236. 1936. Dicranodontium nitidum (Dozy & Molk.) Fleisch., Musci Buitenzorg 1: 87. 1904, hom. illeg. Campylopus nitidus Dozy & Molk., Musci Frond. Ined. Archip. Ind. 5: 139. 1847.

Thysanomitrium uncinatum Harvey, Icon. Pl. 1: plate 22, fig. 5. 1836