Bryopteris diffusa (Sw.) Nees
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Authority
Gradstein, S. Robbert. 1994. Lejeuneaceae: Ptychantheae, Brachiolejeuneae. Fl. Neotrop. Monogr. 62: 216. (Published by NYBG Press)
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Family
Lejeuneaceae
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Scientific Name
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Type
Type. Jamaica and Haiti/Dominican Republic ("Hispaniola"), Swartz s. n. (holotype, S; isotypes, C, S, STR).
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Synonyms
Jungermannia diffusa Sw., Lejeunea diffusa (Sw.) Spruce
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Description
Species Description - Dioicous. Plants up to 20 cm long, laxly dichotomous with very long branches. Branches and stems as in the genus. Leaves oblong or ovate-oblong, about 1.5-2 × 1-1.3 mm, obliquely spreading, on older stem portions sometimes falcate, apex sharply apiculate, rarely obtuse, margins entire, rarely with a few small, bluntish teeth near apex, dorsal base strongly auriculate, ventral margin plane or slightly incurved near the keel; median leaf cells 35-50 × 15-25 µm, trigones and intermediate thickenings as in the genus, rather small; oil bodies (P. Geissler, in sched.) c. 10 per cell, homogeneous. Lobules up to l/4× leaf length, ovate, inflated, free margin inflexed in lower half, plane in upper half and with 3(-4) long, unequal teeth, first and third usually smaller than second tooth, averaging 3-8 cells long, uniseriate to triangular from 2-4 cells wide base, sometimes one of these teeth reduced or enlarged and equalling the second tooth in size, second tooth very large, triangular to lanceolate, 6-20 cells long and 3-8 cells wide, its margins entire or with 1-2 short accessory teeth; occasionally a small fourth tooth present; hyaline papilla on the inner surface near the proximal base of the first tooth. Underleaves obdeltate-subquadrate, about 3.5× stem width, 0.7-1.1 × 0.9-1.2 mm, apex rounded to truncate, sharply toothed, margins plane or narrowly recurved, entire, bases rather abruptly narrowed and folded, distinctly decurrent, insertion line arched; rhizoids arising from rather large, swollen area at underleaf base, normally rudimentary or lacking. Androecia: male bracts with obtuse to apiculate apices. Female bracts with weakly dentate lobe margins and more strongly dentate to lacerate lobules. Perianths rare. Terpenoids: striatene, various acetates and a small quantity of pinguisane-type sesquiterpenes (Gradstein et al., 1985).
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Discussion
Bryopteris diffusa is a very distinct taxon and due to its laxly dichotomous habit and large size can hardly be confused with any other species. From B. filicina it differs in many respects (see Key), particularly its entire leaf margins, large lobule teeth, broad underleaves with arched insertions, and larger leaf cells with relatively small trigones. A further difference is seen in the halfleaves of the Frullania-type branches of the two. In B. diffusa the half-leaf is inserted across the dorsal base of the branch and entirely covers the lower dorsal surface of the branch, which therefore is visible only after removal of the half-leaf. In B. filicina, however, the half-leaf is inserted on the lateral, adaxial surface of the branch and is positioned in front rather than on top of the branch, which as a consequence can be observed in dorsal view without removal of the half-leaf. A half-leaf similar to the one found in B. diffusa is also present in Ptychanthus.
The striking differences between Bryopteris filicina and B. diffusa would seem to warrant their placement in separate sections or subgenera were it not that the differences are bridged by the two other species known in Bryopteris: B. gaudichaudii Gott. (Madagascar and Réunion) and the fossil B. succinea Grolle (Micenic amber of the Dominican Republic). Bryopteris gaudichaudii is superficially similar to B. diffusa by its forked branching and large underleaves with deeply arched insertions. Yet, the lobules of B. gaudichaudii are untoothed as in B. filicina and the leaves are somewhat toothed. Bryopteris succinea, known only from a single shoot fragment with androecia, has leaves similar as in B. filicina but the underleaf insertions are arched like those of B. diffusa. Unfortunately, the branching habit remains unknown in B. succinea. The distributions and relationships of the four species are clearly suggestive of an old, possibly Gondwanan origin of the genus (see Stotler & Crandall-Stotler, 1974; Grolle, 1984).Bryopteris diffusa shows considerable variation in the size of the lobule teeth. Usually the median tooth is much larger than the others but sometimes they are about equal in size and occasionally the first tooth is the largest. This variation can be observed on leaves of single stems. Branch leaves often have smaller teeth than stem leaves. In other respects the species is rather stable. The leaf apex is almost always apiculate (rarely obtuse) and the margins of the lobes are entire except for an occasional bluntish tooth near apex. The depth of the underleaf insertion varies somewhat and rather deeply arched under leaf insertions were observed in collections from Venezuela. The under leaf bases, moreover, were unusually longly decurrent in these specimens.Gynoecia are common throughout the range of the species but perianths are rare and were mostly observed in collections from South America. Their restricted occurrence apparently correlates with the uneven distribution of the male plants, which were rather common in the collections from South America but were virtually lacking in materials from the West Indies and Central America. -
Objects
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Distribution
Scattered throughout tropical America, at elevations from about 100 to 1500 m. Bryopteris diffusa has a somewhat disjunct, submontane range and is apparently lacking in the Lesser Antilles and in most of the Andes. The species occurs in virgin and disturbed evergreen forests and woodlands and grows on tree trunks, branches and twigs. On twigs the species usually forms long, pendent festoons.
Mexico North America| Chiapas Mexico North America| Veracruz Mexico North America| Nicaragua Central America| Granada Nicaragua Central America| Costa Rica South America| Cartago Costa Rica Central America| Guanacaste Costa Rica Central America| Limón Costa Rica Central America| San José Costa Rica Central America| Cuba South America| Jamaica South America| Haiti South America| Dominican Republic South America| Monte Cristi Dominican Republic South America| Barbados South America| Venezuela South America| Bolívar Venezuela South America| Carabobo Venezuela South America| Falcón Venezuela South America| Lara Venezuela South America| Miranda Venezuela South America| Yaracuy Venezuela South America| Zulia Venezuela South America| Trinidad and Tobago South America| Guyana South America|