BFNA Title: Douinia
Scapaniaceae – Douinia
XXX. DOUINIA (Jensen) H. Buch. Comment. Biol. 3(1): 13. 1928 * [For Charles Isidore Douin, French bryologist, 1858--1944]
Paul L. Redfearn, Jr.
Plants small, olive green to yellow-green, leafy shoots 1.5--1.8 mm wide, dry plants curling up and away slightly from the substrate. Stems to 2 cm, cortex not clearly differentiated from interior region, cortical cells in 1--2 layers. Leaves alternate, ± transversely inserted, complicately 2-lobed, fold not keeled and mostly not sheathing the stem, nearly, straight, ca 1/3 the length of ventral lobe; dorsal lobe, long narrow, triangular, sharply acute, usually entire; ventral lobe ovate, long, narrow, triangular, usually entire, much wider than dorsal lobe, usually 1.3--(1.1--1.7) times as long as dorsal lobe, sharply acute, usually entire; medial laminal cells of ventral lobe isodiametric, ± 20 \mu, walls not or little thickened, trigones small to medium. Underleaves absent. Sporophyte capsule ovoid, 3--4-stratose. Elaters 1-spiral or only with rings, occasionally with 2 spirals that are not wound parallel with each other. Spores with blunt spines.
North America, Europe,
Douinia is similar to Diplophyllum, but is distinguished by sharply acute leaf apices and a distinctive olive to yellow-green color and rather waxy appearance, perianth shape and mouth, leaf fold, apparent lack of gemmae, and its epiphytic ecology.
SELECTED REFERENCES Frye, T.
C. and L. Clark. 1946. Hepaticae of
1. Douinia ovata (Dickson) H. Buch. Comment. Biol. 3(1): 14. 1928
Jungermannia ovata Dickson, Pl. Crypt. Brit. 3:11. 1793
Plants growing in patches or singly among other bryophytes. Stems 0.6 --2 cm long, 1.5--2.8 mm wide, prostrate to ascending, simple to ± dichotomously branched, sometimes with innovations beneath the female perianths; cortical cells incrassate, the cuticular wall the thickest, interior cells thin walled; rhizoids few, present to near the stem tip, long, colorless. Leaves approximate to imbricate, fold straight to moderately concave, 250--460 \mu, the angle rounded to obtuse; dorsal lobe transversely inserted, not decurrent, diverging 10--65º from the stem, moderately appressed to stem, lanceolate with free tip narrowly triangular, 600--900 x 170--300 \mu, arching to about middle of stem, apex sharply acute, margin usually entire, sometimes slightly crenulate to denticulate; ventral lobe margin slightly to distinctly lying over the lobe immediately behind it, little to moderately arched upward toward the stem, ending distinctly to usually strongly above the level of the base of the fold, not decurrent to barely decurrent, diverging 40--70 º with the stem, ovate to narrowly ovate, 0.6--1 x 30--460 \mu, 2.--3.4 times as long as the fold, apex sharply acute, margin entire to occasional crenulate with a few indistinct teeth; cells of middle and ventral half of leaf isodiametric, ± 20 \mu, distal cells 14---20 \mu, 11--16 \mu along ventral half, cavity rounded due to distinct trigones; oil bodies 3--8, covering 1/4--1/2the cell cavity; cuticle smooth to minutely verruculose, often giving the leaves a waxy appearence. Sexual condition: male plants intermingled with female plants, more delicate, inflorescence usually terminal, bracts about 12, similar to leaves; female bracts with two equal lobes, somewhat larger than leaves of sterile shoots; perianth 3/4--5/6 emergent, ovoid to cylindric-ovoid, deeply plicate to middle or below, with many lobes or long irregular branches that are often ciliate and antleroid, ultimate branches to 10 cells long. Sporophyte with capsule reddish brown to vinaceous red. Spores 12--21 \mu.
regions, subarctic to Arctic in coniferous forest,
shaded, siliceous rock outcrops of cliffs and trunks of conifers,
hardwoods, among other mosses of high
branches in suboceanic forests; 50--1350 m; B.C., Nfld.
and Labr. (Nfld.);