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ceratodon moss, fire-moss

Habit Plants in open to dense tufts, turfs, or mats, green, dark green, brownish green, light green or yellow-green, usually darker proximally, often tinged reddish brown or purple. Plants minute or rather small to medium-sized, gregarious or loosely to densely tufted.
Stems

(0.2–)1–3(–4) cm.

erect, simple or forked, with a central strand.

Leaves

crowded, erect-patent to contorted or somewhat crisped, rarely straight when dry, lanceolate, ovate-lanceolate, or triangular-lanceolate, 0.35–2.8 mm, margins recurved to near apex or rarely plane, irregularly serrate to uneven or smooth distally, apices acute to short-acuminate or, rarely, obtuse;

costa strong, sub-percurrent to excurrent, sometimes as a long, smooth awn, medial laminal cells (6.5–)8–12(–14) µm, cell walls even, usually of medium thickness, often somewhat thicker and rounded at the cell angles.

mostly lanceolate, acuminate or subulate, straight or somewhat curved, rarely sheathing at base; in numerous rows (2 rows in Distichium);

costa single, well developed, subpercurrent to excurrent, in section with 1 row of guide cells and 2 stereid bands, adaxial band sometimes much reduced;

lamina cells smooth (± roughened in subula in Distichium);

basal cells elongate, narrower towards the margins, those of basal angles not differentiated or forming a marginal border;

distal cells isodiametric or short-rectangular to elongate, walls firm.

Seta

1–3(–4) cm, various shades of red, orange, or yellow.

short to ± elongate, yellow to orange, reddish brown, brown, or reddish purple;

capsules immersed to emergent and subglobose to long-exserted and ± cylindric, erect to inclined or pendulous, often ± curved or asymmetric; cleistocarpous, gymnostomous, or peristomate;

annulus, when present, usually of 2–3 rows of larger cells, deciduous;

peristome, when present, single, of 16 teeth, variously split into two terete filaments or perforate to near the base;

operculum conic to short-rostrate.

Sexual condition

dioicous, autoicous, paroicous, or synoicous;

perigonia axillary or on short branches adjacent to perichaetia, or terminal on separate plants;

perichaetial leaves not markedly differentiated or with a longer, broader sheathing base and shorter subulate apex.

Capsule

oblong to long-cylindric, (1–)2–2.5(–3) mm, smooth to strongly sulcate when dry;

free to united at their nodes, finely papillose to spinulose-papillose, dark red and bordered to completely pale and absent borders.

Calyptra

cucullate, rarely mitrate.

Spores

(10–)11–14(–17) µm.

spheric to ovoid or ± reniform, finely to coarsely papillose, verrucose, or somewhat vermicular or reticulate.

Specialized

asexual reproduction occasional, as multicellular filamentous gemmae borne in axils or along stems, or as specialised tubers or filamentous propagules on rhizoids.

Ceratodon purpureus

Ditrichaceae

Distribution
from USDA
Nearly worldwide
[WildflowerSearch map]
Cosmopolitan; greatest occurrence in temperate regions
Discussion

Subspecies 4 (3 in the flora).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Genera 25, species ca. 140 (9 genera, 25 species in the flora).

Species of Ditrichaceae usually colonize soil, rarely wood, and some species have a distinct preference for calcareous substrates. The family is poorly defined and separated from Dicranaceae primarily on peristome characteristics, with the teeth divided into terete rather than flat filaments, and the general absence of vertical pit-striations. In some species, however, oblique ornamentation is present, at least in the distal portion of the teeth. W. R. Buck and B. Goffinet (2000) included 25 genera, with one hybrid genus, Pleuriditrichum, in the family. The inclusion of at least some of the genera seems somewhat anomalous. Within the flora, Ceratodon, Distichium, Ditrichum, Saelania, and Trichodon are peristomate, while Cleistocarpidium, Eccremidium, Pleuridium, and Pseudephemerum are cleistocarpic. Although in this treatment it is included in Ditrichaceae, Pseudephemerum was placed in Dicranaceae by Buck and Goffinet.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key
1. Plants usually of various shades of green to red-brown; seta red to dark brown; capsule inclined to horizontal, oblong to cylindric, strumose, deeply sulcate when dry, usually red to red-brown to purplish, occasionally light brown
subsp. purpureus
1. Plants pale green to yellow-green to yellowish brown; seta pale yellow to yellow-orange, rarely reddish; capsule slightly inclined to erect, narrowly cylindric to cylindric, not or weakly strumose, smooth to sulcate when dry, usually pale brown to yellow (golden) -orange
→ 2
2. Stems usually less than 0.5 cm; distal leaves relatively compact, straight to slightly twisted when dry, usually forming a comal tuft, slightly spreading when wet, 0.6-1.2 mm, margins often entire; costa long-excurrent as a smooth awn on many leaves, awns sometimes as long as leaf blade
subsp. conicus
2. Stems usually greater than 1 cm; distal leaves more open, usually crisped when dry, not forming a comal tuft, spreading when wet, 1.2-1.8 mm, margins often toothed; costa percurrent to slightly excurrent
subsp. stenocarpus
1. Leaves in two rows, base ± sheathing, abruptly narrowed to a ± roughened subula.
Distichium
1. Leaves in more than two rows
→ 2
2. Leaves glaucous blue-green.
Saelania
2. Leaves yellow-green to green or brownish green, never glaucous blue-green
→ 3
3. Leaves squarrose from a sheathing base, subulate, the subula tubulose and strongly prorulose abaxially.
Trichodon
3. Leaves lanceolate to subulate, the base ± sheathing or not, not squarrose
→ 4
4. Stems generally elongate, 0.5-4 cm or sometimes longer; capsule, when present, peristomate
→ 5
4. Stems generally very short, 0.2-0.8 cm; capsule, when present, immersed and cleistocarpic
→ 6
5. Leaves lanceolate, ovate-lanceolate or triangular-ovate to obovate, margins recurved; seta reddish purple to yellowish orange, capsule erect to inclined, strongly sulcate when dry.
Ceratodon
5. Leaves lanceolate to subulate, margins mostly plane, occasionally weakly recurved; seta pale yellow to yellow to orange to reddish brown, capsule erect to suberect, not sulcate when dry
Ditrichum
6. Leaves loosely erect, subulate-acuminate from a lanceolate base, margins sharply serrate distal to the shoulders, costa excurrent, filling subula; seta stout, arcuate; capsule laterally emergent, pendulous.
Eccremidium
6. Leaves erect-spreading or appressed or reflexed-recurved, oblong to lanceolate or subulate, margins plane, serrulate towards apex, costa subpercurrent to excurrent; seta short, erect to curved, not arcuate; capsule erect to inclined, not pendulous
→ 7
7. Leaves reflexed-recurved, lanceolate from an ovate base, margins plane, entire, serrulate at the flat apex; laminal cells thin-walled, proximal cells larger, rectangular, distal cells rhombic; capsule ovoid.
Pseudephemerum
7. Leaves erect-spreading or appressed, oblong to lanceolate with subulate to acuminate tips, margins plane, entire to serrate or abruptly toothed; lamina cells quadrate-rectangular proximally, becoming irregularly rhomboid to trapezoidal and elongated distally; capsule ovoid to elliptic
→ 8
8. Stem leaves 2-4 mm, loosely erect, subulate from an ovate-lanceolate to narrowly obovate base, entire, serrulate along subula; capsule immersed, ovoid, broadest at base, whitish, spore sac orange.
Cleistocarpidium
8. Stems leaves 0.5-2 mm, erect-spreading or appressed, imbricate to spreading, oblong to lanceolate with subulate to acuminate tips, entire to serrate or abruptly toothed; capsule immersed, ovoid to elliptical, orange to brown.
Pleuridium
Source FNA vol. 27, p. 446. FNA vol. 27, p. 443. Author: Rodney D. Seppelt.
Parent taxa Ditrichaceae > Ceratodon
Sibling taxa
C. heterophyllus
Subordinate taxa
C. purpureus subsp. conicus, C. purpureus subsp. purpureus, C. purpureus subsp. stenocarpus
Ceratodon, Cleistocarpidium, Distichium, Ditrichum, Eccremidium, Pleuridium, Pseudephemerum, Saelania, Trichodon
Synonyms Dicranum purpureum, C. purpurascens, C. purpureus var. purpurascens, C. purpureus var. xanthopus
Name authority (Hedwig) Bridel: Bryol. Univ. 1:480. (1826) Limpricht
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