BFNA Title: Pterigynandrum
Author: D. H. Vitt 
Date: September 17, 2004
Edit Level: R Brum+
Version: 1b

Bryophyte Flora of North America, Provisional Publication
Missouri Botanical Garden
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 Edit Level R Brum+




XXX. PTERIGYNANDRUM Hedwig, Spec. Musc. Frond., 80.  1801 * [Alluding to the lateral position of male and female inflorescences]

Dale H. Vitt


Plants slender, green to yellow-green.  Stems freely and irregularly branched, forming pendent to prostrate, smooth mats; paraphyllia none or rare.  Leaves erect to homomallous, somewhat concave, closely spaced, oblong-elliptic, blunt to acute; margins reflexed proximally, serrulate distally; costa short and double; laminal cells oblong-rhombic, generally thick-walled, prorulose abaxially; alar cells small and subquadrate.  Sexual condition dioicous.  Sporophytes not common.  Capsules erect, cylindric, smooth; peristome double, short.  Calyptra cucullate.


Species 1 (1 in the flora): North America, Europe, Asia, Africa.


1. Pterigynandrum filiforme Hedwig, Spec. Musc. Frond., 81. 1801


Stem leaves imbricate, erect, somewhat falcate to homomallous, 0.6--1 mm, oblong-elliptic; margins narrowly reflexed below, erect and serrulate above; distal laminal cells oblong to rhombic, curved, abaxially prorulose.  Seta 5--15 mm. Capsule 1--2.5 mm, symmetric; urn cylindric, erect; peristome diplolepidous, exostome teeth 16, short, lanceolate, endostome of 16 stout linear segments; calyptra cucullate.  Spores 11--13 µm.


Mesic, acidic boulders and rock shelves in the western montane forests and on acidic rocks throughout the eastern Canadian shield country; Greenland; Alta., B.C., N.B., Nfld., N.W.T., N.S., Ont., P.E.I., Que., Yukon; Alaska, Calif., Colo., Idaho, Maine, Mass., Mich., Minn., Mont., N.H., N.Y., N.C., Oreg., Penn., S.D., Tenn., Vt., Va., Wash., W.Va., Wis., Wyo.; Europe; West Indies; Central America; Asia.


The slender, sleek, braided stems trailing down the sides of acid rocks are characteristic of Pterigynandrum filiforme.  The somewhat curved, ovate, rather blunt leaves; and rhombic, coarsely prorulose leaf cells are additional identifying features.