The English flora - SeaweedAfrica

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28 MUSCl-ACROCARPI-PERTSTOMI. [Didymodon.
From this, Trichostomiim ellipticum may be known by its more crowded
spreading acuminated leaves, the glossy rigid more oval capsule, and its
much longer and perfectly straight beak to the lid, and deeply divided
teeth of the peristome.
16. Didymodon. Hediv. Didymodon.
Seta terminal. Peristome single, of 16 or 32 teeth approaching
in pairs or united at the base. Calyptra dimidiate. (Muse.
Brit. t. 2.)—Named from eiidvpog, twin, and o^m, a tooth ; from
the approximation of the teeth in pairs,
1. D. purpureas, Hook, and Taylor, (purple Didymodoii);
stems scarcely branched, leaves lanceolate acuminate carinated
their margins recurved entire, capsule ovato-cylindraceous
oblique substrumose furrowed when dry, lid conical. Muse. Brit,
ed. 1. p. 65. ed. 2. p. 113. t. 20. Drum. Muse. Scot. v. 2. n. 49.
—Dicranum purpureum, Hedw. Sp. Muse. t. 36. Turn. Muse.
Hib. p. 72. Fl. Brit. p. 1217. E. Bot. t. 2262.—D. purpurascens,
D. Celsii, and D. intermedium, Hedw.—D. strictum, Sm.—
D. papillosum, Brid.— Trichostomum papillosum, Sm Bryum
Celsii and Mnium purpureum, Linn, and Bryum papillosum,
strictum, tenue and bipartitum of Dicks, may confidently be re-
ferred here.
On the ground and on moist banks, most abundant. Fr. Spring.
Variable as this plant assuredly is in its stems and foliage, it is very
constant in the form of the fruit, by which it may always be known.
The peristome is that of a Didymodon, but the
nected by transverse bars.
pairs of teeth are con-
2. D. inclindtus, Sw. (inclined-fruited Didymodon); stems
somewhat elongated, leaves bifarious from a sheathing base
subulate, capsule ovate inclined smooth, lid conical. Swartz,
Muse. Suec. p. 28. Drum. Muse. Scot. v. 1. n. 53.— Cynontodium
inclinatum, Hedw. Sp. Muse. p. 58.— Grimmia inclinata, Fl. Brit,
Swartzia inclinata, Hedw, St. Cr.
p. 1196. E. Bot. t. 1824.
v. 2. t. 27. Bryum inclinatum, Dicks.
Usually on mountain rocks ; but rare. On the sands of Barrie, near
Dundee, growing with Weissia nigrita; Mr. Don. Fr. Aug.—The teeth
are so broad in this species that were it not for their approximation in
pairs, we should certainly rank it with the Weissice.
3. D. nervosus, Hook, and Taylor, (thick-nerved Didymodon);
leaves obovate shortly apiculate their nerve incrassated above,
capsule ovate erect, lid shortly rostrate. Muse. Brit. ed. 1. p. 66.
ed. 2. p. 115. t. 20.— Grimmia atro-virens, E. Bot. t. 2015.
On dry banks, especially in maritime situations in the south of
England, Wales, and Ireland. Fr. Spring.—This species has wider
leaves than its congeners and a nerve remarkably thickened upwards.
The 32 teeth approach in pairs, and are, as in D.purpureus, connected
by transverse bars.
4. T).flexifolius, Hook, and Taylor, (wavy-leaved Didymodon);
steins more or less elongated, leaves erecto-patent oblongo-ovate
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