BFNA Title: Dendroalsia
Author: C. C. Newberry 
Date: February 25, 2008
Edit Level: R
Version: 3

Bryophyte Flora of North America, Provisional Publication
Missouri Botanical Garden

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Dendroalsia - Cryphaeaceae


XX. DENDROALSIA E. Britton in Brotherus, Nat. Pfl. 1(3): 859. 1906  *  [Greek dendros, tree, plus the generic name Alsia, suggesting a dendroid Alsia]

Clayton C. Newberry


Plants in thick loose mats.  Secondary stems erect-ascending, densely foliate.  Paraphyllia abundant.  Leaves broadly ovate to ovate-lanceolate, distinctly 5-ranked along the stem.  Sexual condition dioicous.  Seta longer than the perichaetial leaves.  Capsule rarely exceeding 2.5 mm; stomata mostly basal, phaneroporus; annulus 2-seriate, evanescent; peristome double; endostome segments arising from a low basal membrane; operculum conic-rostrate to oblique-rostrate.  Calyptra cucullate, naked.


Species 1, varieties none:  western North America.


The characterization of Dendroalsia as given by D. H. Norris and J. R. Shevock (2004) is accurate and descriptive:  Dendroalsia is especially easy to recognize when the plant is dry---each of the branches curls downward so that the entire branched system resembles a clenched fist, with its curved fingers representing the branches.”  When wet, the stems and branches uncurl to form broad, handsome fern-like tails orthotropic to the substrate (usually a tree trunk or vertical rock face).


SELECTED REFERENCES Norris, D. H. and J. R. Shevock.  2004.  Contributions towards a bryoflora of California II.  A key to the mosses.  Madroño 51: 133--269. Manuel, M.  1974.  A revised classification of the Leucodontaceae and a revision of the subfamily Alsioideae.  Bryologist 77: 531--550.


1. Dendroalsia abietina (Hooker) E. Britton, Bull. Torrey Bot. Club 32: 263. 1905


Neckera abietina Hooker, Musci Exotici 1: 7. 1818


Plants robust or unusually large, stiff, wiry and dark green to green when dry, softer and bright green when moist, tail-forming.  Primary stems to 10--15 cm, plagiotropic, tightly adhering to the substrate, stoloniform, densely rhizoidal.  Secondary stems usually 10--12(--25) cm, circinate and curling downward when dry, opening and orthotropic when moist, proximally stipitate, distally pinnate to 2-pinnate branching and frondiform, more rarely nearly dendroid; internal cells almost all incrassate, the cortical cells particularly so, these 12--18 cells thick and darkly pigmented, ± grading into slightly larger, less pigmented and less incrassate medullary cells; central strand lacking; paraphyllia and rhizoids both abundant throughout the stem, the paraphyllia multiform, 1- to multiseriate to narrowly subulate, often branching; pseudoparaphyllia investing the branch buds, subulate to deltate to subfoliose, irregularly dentate.  Lateral or tertiary branches common, ± equal, to 30 mm, often bearing even smaller (less than 10 mm) quaternary branchlets; internal anatomy similar to that of main stem, only smaller, the cells less pigmented and less incrassate, the cortex 4-6 cells thick.  Stem leaves 2--3 x 1--1.5 mm, erect to erect-patent when dry, spreading when moist, concave, ± plicate; leaf apex acute to acuminate, the apical cells isodiametric to oval-rhombic, incrassate, often prorate; median cells more linear, 10-25 × 5-6 µm, incrassate, occasionally prorate; leaf base slightly decurrent, the basal cells incrassate, roughly isodiametric, filling the basal angle of the leaves; margin recurved and entire at the base, usually increasingly plane and dentate towards the apex; costa strong, subpercurrent to percurrent to barely excurrent, occasionally sinuous, increasingly dentate distally.  Branch leaves similar to main stem leaves but usually smaller and narrower, 1.5-2 × 1 mm.  Perigonia common along the frondose portions of the secondary stem, occasional on the tertiary and even the quaternary branchlets, to 2 mm; perigonial leaves smallish, deltoid-apiculate to lanceolate-apiculate, the cells prorate, the margin increasingly serrate distally, the median margin revolute; antheridia to 1 mm, fusiform.  Perichaetia borne ventrally mostly on the secondary stem, occasionally on the tertiary stems; perichaetial leaves grading from short-deltoid to deltoid-apiculate or longer, sheathing, truncate-apiculate, to 2.5 mm, the basal cells thin-walled, rectangular at 4-5:1, the median and distal cells incrassate, elongate at 3-6:1.  Seta brown, short, 0.7-2 (-3) mm, straight.  Capsule brown to red-brown, 2-2.5 × 1 mm, barely exserted, erect-symmetric, oblong-ovoid to ovoid, plicate when dry, the surface smooth; operculum conic-rostrate; exostome teeth 16, white, to 0.6 mm, linear-subulate, trabeculate, coarsely papillose distally, less so proximally; endostome segments white, slender, as long as the exostome teeth, narrowly subulate, slightly carinate, strongly papillose, persistent, basally fused; cilia lacking.  Spores spherical, pale brown, papillose, 15-25 \um.


Often widely spreading, covering whole trunks, limbs and branches of trees, or large surfaces of rocks; 0--1000(--2000) m: B.C.; Alaska, Calif., Idaho, Mont., Oreg., Wash.; Mexico (Baja California).


Dendroalsia abietina is an important component of the bryoflora of far western North America.  Its primary range extends from the Channel Islands and Los Angeles County northward throughout cismontane California, Oregon and Washington, to Vancouver Island (Georgia Straits) and southwestern British Columbia mostly south of 50˚ north latitude.  Southern and northern disjuncts occur on Guadalupe and Cedros Islands off the west coast of Baja California and on Baranof Island near Sitka, Alaska, respectively.  Transmontane disjuncts have been reported in some perennially mesic microhabitats, such as cold air traps in Lava Beds National Monument, California, or in the cedar-hemlock-larch ecozone of northern Idaho, northwest Montana and southeast British Columbia (the so-called “interior wet zone,” an area noted for many maritime disjuncts).  Dendroalsia abietina is one of the most common epiphytes throughout its primary range.  It is often the dominant epiphyte on Arbutus, Chrysolepis, Lithocarpus and Quercus bark, covering the entire trunk and leaving little space for competition.  Although in southern California D. abietina has been reported as common along the coast, throughout most of its range it usually grows just back from the maritime spray zone and more abundantly back from the first coastal ridges inland (D. H. Norris and J. R. Shevock 2004).  It becomes extremely common in the Inner Coast Range and the oak woodlands of Sacramento Valley, southern Oregon and Willamette Valley.