BFNA Title: Zelometeorium
Author: M. Ignatov & W. Reese
Date: October 6, 2009
Edit Level: R
Version: 2

Bryophyte Flora of North America, Provisional Publication
Missouri Botanical Garden

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XX. ZELOMETEORIUM M. G. Manuel, J. Hattori Bot. Lab. 43: 110. 1977 * [Greek zelo, emulate, envy, or rival, and meteorium, alluding to the type genus of the original family]


M. S. Ignatov

W. R. Reese


Plants rather robust, stems creeping along branches and twigs of trees, with numerous pendent stems, forming intricate tangles, sometimes distally filiform, green or more commonly yellowish to brownish green, blackish in old parts. Stems both creeping and pendent flexuose, with weak central strand, sometimes lacking, having similar foliage and branching whether creeping or pendent, although strongly variable, foliage terete; branching uneven, sometimes fairly regularly pinnate; branches straight to flexuose; axillary hairs 3--4 celled, one proximal cell short, brownish, distal cells elongate; juvenile branch leaves broadly triangular. Stem leaves in dense foliage erect-spreading to squarrose from a clasping base, broadly ovate, acute to acuminate, broadest at 1/2--1/4 of leaf length, rounded to a cordate base, margins plane or recurved proximally, subentire to serrulate; costa slender, reaching 0.6--0.8\x leaf length, ending in a small abaxial tooth; juxtacostal basal cells short-rectangular in 1--2 rows, with thicker and pitted walls, more pellucid, grading to adjacent cells; forming an indistinct pellucid group in leaf corners; mid leaf cells linear; leaves in loose foliage erect to erect-spreading from a clasping base, narrowly to broadly ovate, abruptly acuminate into a long acumen, often piliferous and flexuose; rounded to base and auriculate, costa reaching 0.3--0.7 of leaf length, lacking a spine; juxtacostal basal cells shorter and with thicker and pitted walls, not distinctly differentiated from mid leaf cells, submarginal cells in leaf corners, usually only 2--4, sometimes slightly larger and pellucid; mid leaf cells linear. Branch leaves not different from stem leaves. Sexual condition dioicous; perichaetial leaves erect with erect to spreading acumens; entire proximally, serrulate distally; costa extending to base of acumen. [Seta reddish, short, straight to curved, rough. Capsule exserted beyond perichaetial leaves, erect, cylindric; annulus separating by fragments; operculum conic-rostrate; peristome hygrocastique, open when wet; exostome teeth narrowly lanceolate, slightly papillose basally, strongly papillose distally; endostome with low basal membrane, segments as long as exostome teeth, strongly papillose distally; cilia lacking. Calyptra mitrate, pilose. Spores smooth to slightly papillose, 14--23 /um.]


Zelometeorium has for long been treated as a member of the tropical and subtropical family Meteoriaceae, although its closest relative, Meteoridium, was considered a member of Brachytheciaceae by some authors (M. Lewis 1992). Results of molecular phylogenetics (M. S. Ignatov and S. Huttunen 2002) definitely indicate the position of both of them within the Brachytheciaceae, a sister family to the Meteoriaceae.


Species 5 (1 in the flora): tropical areas of the Americas and Africa.


SELECTED REFERENCE Manuel, M. G. 1977. A monograph of the genus Zelometeorium Manuel. gen. nov. (Bryopsida: Meteoriaceae). J. Hattori Bot. Lab. 43: 107--126.


1. Zelometeorium patulum (Hedwig) M. G. Manuel, J. Hattori Bot. Lab. 43: 118. 1977 C


Hypnum patulum Hedwig, Sp. Musc. Frond., 279. 1801; Meteoriopsis patula (Hedwig) Brotherus


Stems to 15 cm; branches to 15 mm. Stem leaves 1--1.6 x 0.8--1.2 mm (squarrose leaves in densely foliate stem parts) or  1.5--2 x 0.45--0.7 mm (erect leaves from moderately loosely foliate stem parts); basal cells to 12 \um wide; midleaf cells 45--70 x 4-6 \um.


Pendent in tangled wefts from shrubs in humid evergreen hammock forests; 0 m; Fla.; Mexico; West Indies; Central America; South America.


The smooth glossy plants of Zelometeorium patula, pendent in loose tangles, with their usually distinctly spreading-squarrose leaves, are easy to recognize. In North America, this moss is known only from Collier and Dade counties, Florida. There is only one collection (1993) of this moss from Florida since 1940, and the species is perhaps in danger of extinction in the flora area due to destruction of habitat. In tropical areas, stems can be much longer, to 47 cm (M. G. Manuel 1977). Sporophytes are very rare, and their description is based on Latin American plants.




Lewis, M. 1992 Meteoridium and Zelometeorium in Bolivia. Tropical Bryology 5: 35--53.


Ignatov, M. S. and S. Huttunen 2002 [2003]. Brachytheciaceae (Bryophyta)---a family of sibling genera. Arctoa 11: 245--296.