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BFNA Title: Douinia |
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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. Species 1:
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. Coastal
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.); |
