Porotrichum longirostre (Hook.) Mitt.
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Authority
Buck, William R. 1998. Pleurocarpous mosses of the West Indies. Mem. New York Bot. Gard. 82: 1-400.
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Family
Neckeraceae
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Scientific Name
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Description
Species Description - Plants medium-sized, to ca. 5 cm tall, stipitate-frondose, in dull- to yellow-green to golden, fairly stiff colonies. Primary stems creeping, secondary stems mostly arising from upturning primary stem, the creeping stem continuing by innovations near the base of the stipe, the secondary stems distinctly stipitate, to ca. 2 cm tall, mostly erect, frondose, irregularly and weakly 2-pinnate, usually complanate-foliate; in cross-section with 3-5 rows of small thick-walled cells, with 6-8 rows in stipe, surrounding large tilinto firm-walled cells, central strand not or weakly differentiated in the primary stem, distinct and of small thin-walled cells in the stipe; paraphyllia absent; pseudoparaphyllia foliose; axillary hairs with 1-2 short brown basal cells and 2-3 elongate hyaline to brown distal cells. Primary creeping stem leaves reduced, widely spaced, pale, appressed, ovate-triangular, 0.5-0.6 mm long, gradually broad-acuminate; margins subserrulate almost throughout, plane; costa short and double or single and ending well below midleaf; cells fusiform, 6-8:1, smooth, thin- to firm-walled, not or scarcely porose; alar cells not differentiated. Stipe leaves wide-spreading, not complanate, ovate-triangular, 1.1-1.4 mm long, ± gradually acuminate; margins subserrulate to subentire above, entire below, plane above, often narrowly recurved below; costa short and double or single and often forked, ending near midleaf; cells linear-fusiform, ca. 20:1, smooth, thin- to firm-walled, slightly porose, becoming shorter and long-rectangular toward the insertion; alar cells few, short-rectangular, thin-walled. Secondary stem (continuation of stipe above branching) leaves complanate, erect-spreading, oblong-ovate, 2.1-2.4 mm long, ± abruptly acute to obtuse-cuspidate, concave; margins serrate above with unicellular teeth, subentire below, plane or ± incurved above; costa single, ending 2/3-3/4 the leaf length, projecting as a small spine at apex or not; cells fusiform, 4-8:1, smooth, ± thin-walled, not porose, not becoming shorter toward the apex except in the cusp, becoming longer, thick-walled and porose toward the insertion; alar cells ca. 4 in extreme angles, small, short-rectangular. Branch leaves erect-spreading, ± complanate, oblong-ovate to oblong-obovate to elliptic, 0.9-1.3 mm long, acute, concave, narrowed to the insertion; margins serrate above with the teeth l(-3)-celled, serrulate almost to base or entire below, plane or recurved below; costa single, ending 1/2-2/3 the leaf length, projecting as a small spine at apex or not; cells fusiform, 4-8:1, smooth, thin- to firm-walled, not or scarcely porose, becoming only slightly shorter above except in extreme apex, becoming thicker-walled toward the insertion; alar cells only 2-4 in extreme angles, subquadrate. Asexual propagula not seen in the West Indies, rare extralimitally as flagellate branches. Dioicous. Sporophytes not seen.
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Discussion
3. Porotrichum longirostre (Hook.) Mitt., J. Linn. Soc., Bot. 12: 461. 1869; Neckera longirostris Hook., Musci Exot. 1: 1. 1818; Climcicium longirostre (Hook.) Brid., Bryol. Univ. 2: 275. 1827; Hypnum porotrichum Müll. Hal., Syn. Musc. Frond. 2: 223. 1851, non H. longirostre Ehrh. ex Brid., Muscol. Recent. 2(2): 154. 1801, nom. illeg.; Porophyllum longirostrum (Hook.) Schimp. ex Paris, Index Bryol. 1015. 1898, nom. illeg.; Thamnium longirostre (Hook.) Kindb., Hedwigia 41: 233. 1902. Plate 48, figures 10-18 Discussion. I have only called two specimens Porotrichum longirostre from the West Indies, and but one of them with confidence (Dominican Republic, 2250 m, Buck 8071, NY). The confusion between P. longirostre and P. mutabile needs further investigation. However, I do think the two species are distinct and that Allen (1994) was in error in synonymizing them. Porotrichum longirostre has wide-spreading, acuminate stipe leaves and ± elliptic branch leaves. In the branch leaves the insertion is narrow so that the leaves are broadest near midleaf and tapered to both ends. Also, unlike some other species of Porotrichum, P. longirostre rarely has flagellate branches, and when present they are few in number. As I understand it, P. longirostre is very common in Central America, but nowhere outside of there. In the West Indies and northern South America it is mostly replaced by P. mutabile. From P. mutabile, P longirostre differs in branch leaves relatively short (about 2.5:1, compared with about 4:1), elliptic to obovate (rather than oblong), with laminal cells scarcely shorter above (rather than noticeably rhombic above). Also, in P mutabile almost all plants have at least some flagellate branches, whereas they are rare in P longirostre. Porotrichum longirostre differs from P. korthalsianum by the more sharply pointed branch leaves.
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Distribution
Range. Mexico and throughout Central America, Colombia, Ecuador, Peru, southeastern Brazil; Hispaniola (Dominican Republic), Puerto Rico; growing on tree trunks and rocks, in humid forests, at 875-2250 m.
Mexico North America| Central America| Colombia South America| Ecuador South America| Peru South America| Brazil South America| Dominican Republic South America| Puerto Rico South America|