Trematodon longicollis Michaux 1803

Trematodon longicollis is much like T. ambiguus but differs in the relative lengths of capsule urn and neck when dry, and is clearly more southern in distribution. The peristome may occasionally adhere to the operculum on dehiscence and the capsule may then falsely appear gymnostomous.

Plants minute, 2–6 mm high, green to yellowish green, gregarious or scattered. Stems erect, simple or rarely branched. Leaves 1.7–3.6 mm long, contorted when dry, flexuose spreading when moist, oblong to oblong-ovate at base, gradually narrowed from a clasping base to a long, linear-subulate acumen, blunt at tips; margins plane and entire below, slightly recurved and serrulate above; costa strong, percurrent, not entirely filling the acumen; upper and median cells short to moderately rectangular, 18–24 µm × 8–10 µm, firm or somewhat thick-walled; basal cells in the clasping base, oblong-rhomboidal to long-rectangular, 40–90 µm × 8–13 µm, lax, thin-walled. Autoicous. Perichaetial leaves larger than the upper stem leaves. Setae straight, (4–)10–20(–30) mm long, yellow to yellowish brown; capsules inclined, urn short-cylindric, 1.5–2.0 mm long, neck 3.0–5.0 mm long, curved above, strumose at base; opercula slenderly and obliquely long-rostrate; annuli well developed, deciduous; stomata of two kinds; peristome teeth lanceolate, reddish, somewhat perforate, vertically striate on lower 2/3 of the teeth, papillose on the upper 1/3. Spores ca. 20 µm in diameter, strongly papillose.

Leaves ovate-lanceolate to long-subulate from an ovate or obovate base, serrulate at apex; costa percurrent or ending before the apex. Seta long, 10-30 mm. Capsule inclined, curved; neck 2-3 times as long as urn when dry, long-cylindric, strumose at base; peristome teeth 2-fid or irregularly perforate, not fragile, commonly persistent; annulus compound, revoluble.

Distribution: China, widely in Asia, Europe, North, Central, and South America.

Habitat: on soil or rocks.

Trematodon acutus C. Müll., Syn. Musc. Frond. 1: 458. 1848. Trematodon drepanellus Besch., J. Bot. (Desvaux) 12: 283. 1898. Trematodon flaccidisetus Card., Beih. Bot. Centralbl. 17: 5. 1904. Trematodon drepanellus var. flaccidisetus (Card.) Dix., Hong Kong Naturalist. Suppl. 2: 2. 1933. Trematodon paucifolius C. Müll., Syn. Musc. Frond. 1: 459. 1848. Trematodon stristicalyx Dix., Hong Kong Naturalist. Suppl. 2: 3. 1933. Type. China: Zhejiang, Hang-zhou, E. D. Merril 1152 (holotype BM). Trematodon tonkinensis auct. non Besch. (sensu Chinese authors).

Trematodon ambiguus var. longicollis (Michaux) Arnott

Trematodon longicollis Michx. Fl. Bor. Am. 2 : 289. 1803
Trichodon JiexifoUus Ren. & Card. Rev. Bryol. 15: 70. 1888.
Plants light-yellow, gregarious, very variable in size, 2-5 cm. high ; stems simple or branched at base, the sterile branches 10-15 mm. high; fruiting plants shorter, seldom more than 5 mm.: leaves secund or circinnate when dry, 1-3 mm. long, ovate-lanceolate, aAiminate or subulate, the basal lamina clasping, the awn spreading or recurved; margins recurved, serrulate; costa not filling the channelled awn, ending below the toothed apex; lower cells oblong, clear, the upper ones quadrate, irregular; perichaetial leaves 4-5 mm. long, with a longer, sheathing, paler base. Autoicous or pseudodioicous: antheridia terminal on a basal branch: seta variable in length, 1-3 cm.: calyptra cucullate, 2-2.5 mm. long: capsule 4-5 mm. long, variable in size and length of the neck; urn 1-2 mm. long; neck 2-4 mm. long, arcuate, with a goiter, stomatose and tapering to the seta; lid rostrate, 1 mm. or more long, its rim serrate; annulus compound, with an orange-colored base, falling in fragments with the lid; capsulewalls striped with brown, with irregular thick-walled cells; mouth bordered by small rounded cells; peristome with an exserted basal membrane of 3-4 rows of thickened cells; teeth irregularly perforate and striate below, paler and papillose above; spores rough, warty, 21-24/1 in diameter, maturing from April to July.
Type locality: In sandy places. Carolina.
Distribution: Massachusetts to Florida and Louisiana; Mexico; Cuba; also near Pozzuoli, Naples, growing near the Fumaroli, at Solfatara, Italy.

Trematodon longicollis là một loài rêu trong họ Bruchiaceae. Loài này được Michx. mô tả khoa học đầu tiên năm 1803.