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BFNA Title: Gymnocolea |
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2. GYMNOCOLEA (Dumortier) Dumortier,
Rec. d'Obs. 17. 1835 *
[Greek, gymno‑, naked and koleo‑, female sheath, in reference to the large
perianth, not concealed by bracts] Marie L. Hicks Jungermannia sect. Gymnocolea Dumortier,
Syll. Junger. Eur. 52. 1831 Plants creeping with ascending apices, mat forming or erect when crowded,
green to blackish‑brown or scorched in insolated sites. Stems
7‑‑8 cells in diameter, branching terminal, lateral or ventral intercalary,
from older stems, cortical cells thin‑walled, 20‑‑25 \um, little
differentiated from medullary; rhizoids very sparce, scattered along ventral
stem, colorless. Leaves succubous‑oblique, bilobed, the lobes obtuse to rounded,
occasionally acute, often concave; leaf cells subisodiametric, small, 22‑‑30
\um; cuticle smooth, occasionally slightly verruculose; walls without
distinct trigones; oil bodies smooth to slightly granulate. Underleaves
absent or occasional and small, of 1‑‑3 cells from narrow ventral merophytes
of 2‑‑4 cells. Specialized asexual propagation by detached inflated
perianths that float on water; gemmae absent or very rare, angular, brown, 1‑‑2
celled. Sexual condition dioicious. Androecia terminal, spicate, becoming
intercalary, of ventricose bracts similar to leaves
but smaller; antheridia one per bract; stalk 1‑seriate. Gynoecia
terminal on main stem or branch, often with subfloral innovations; bracts
similar to leaves; bracteole absent; perianth exerted, inflated, smooth, the
mouth contracted; perigynium absent. Sporophyte seta
cross section of 8 exterior cells and 4 interior cells; capsule ovoid, brown,
valves 2 cells thick, the walls with nodular thickenings; elaters 120‑‑200 ×
6‑‑9 \um, 2‑spiral, brown; spores 10‑‑18 µm, finely papillate, brown. Species 6 (2 in the flora); cool parts
of the Northern Hemisphere and South America. SELECTED REFERENCES Schuster, R. M. 1969. The Hepaticae and Anthocerotae of North
America, Vol. II. New York. 1.
Leaf lobes with obtuse or rounded apices; gemmae absent; perianths
inflated, easily detached . . . 1.Gymnocolea inflata 1.
Leaf lobes with acute apices; gemmae rare; perianths uncommon, not
easily detached . . . 2. Gymnocolea acutiloba 1. Gymnocolea inflata (Hudson) Dumortier, Rec. d'Obs. 17.
1835
Jungermannia inflata Hudson, Fl. Angl. ed. 2. 2:
511. 1778 Plants with shoots 5‑‑25 × 0.75‑‑1.2 mm, scattered among mosses or in
crowded mats, green in shade or brownish‑black in exposed sites. Stems
slender, 130‑‑300 \um, branching irregular, terminal or ventral intercalary. Leaves
distant to scarcely imbricate, spreading, flat or more often concave, as long
as wide or slightly longer, 400‑‑900 × 350‑‑800 µm, 2-lobed 1/4‑‑1/3, the
sinus narrow, the lobes obtuse to rounded, entire; median leaf cells 22‑‑27 x
25‑‑30 \um, marginal cells 20‑‑24 \um; cuticle smooth, walls evenly
thickened; trigones absent; oil bodies 4‑‑8 per cell, ovoid or spherical, 3‑‑4
× 5‑‑6 \um, finely granulate. Underleaves absent. Specialized
asexual propagation by detached, unfertilized, inflated perianths that
float on water; gemmae absent. Androecial bracts up to 8 pairs,
contiguous, concave, 2-lobed. Gynoecia commonly with subfloral
innovations; bracts similar to leaves in shape, slightly larger; perianths often
present, exerted well above bracts, globose to oblong, inflated, large
compared to the size of the shoot; mouth contracted, dentate‑lobulate; easily
detached from stem. Igneous rock outcrops subject to at
least periodic seepage, often in direct sunlight; also around rock pools and
in bogs; e, w, nw Greenland; Miquelon; Alta., Ark.,
B.C., Man., Nfld., N.S., Nun., Ont., Que., Yukon; Alaska, Calif., Colo.,
Conn., Maine, Mass., Mich., Minn., N. C., N.H., N.J., N.Y., Oreg., Pa.,
S.Dak., Tenn., Vt., Wash., Wyo.; Europe; Asia (Japan). The variety Gymnocolea inflata
var. heterostipa
(Carrington & Spruce) K. Müller, a dubious taxon with frequent small
intercalary branches and small underleaves, has been recognized from plants
collected in East Greenland and Minnesota.
This plant is doubtfully distinct and its gametophytic differences may
be an environmentally induced variation.
In Europe, where the variety was first recognized, no distinct limits
have been found between this variety and the typical form of Gymnocolea inflata. 2. Gymnocolea acutiloba (Schiffner) K. Müller, Rabenh. Krypto. Fl. 6: 745. 1910
Lophozia acutiloba Schiffner, Hedwigia 48: 187.
1909 Plants with shoots 10‑‑15 × 0.6‑‑0.9 mm, forming mats, green to brown or
blackish. Stems 100‑‑180 µm, sparingly branched, the branches terminal,
occasionally intercalary. Leaves remote to slightly
overlapping, nearly flat, ovate‑quadrate, slightly longer than wide, 370‑‑600
x 320‑‑500 \um, 2-lobed 1/3‑‑1/2 , with a narrow sinus and subacute to acute
lobes ending in 1‑‑2 single cells; lateral leaf margins often with a small
tooth; leaf cells subquadrate, 22‑‑28 \um, walls slightly thickened, often
brownish; trigones not developed; oil bodies 3‑‑8 per cell, ovoid or
spherical 4‑‑6 x 5‑‑8 \um, smooth or slightly granular. Underleaves
absent or vestigial, of small cilia or slime papillae. Specialized
asexual propagation usually absent or rarely by gemmae on margins of leaf
lobes, angular, 14‑‑18 µm, 2‑celled, brown.
Plants usually sterile. Gynoecia
with bracts similar to leaves in shape, larger; perianth rarely produced, not
easily detached, inflated, clavate, the mouth dentate. Igneous rock that are perhaps copper‑bearing,
where they may occur with other rare species such as Cephaloziella massalongoi
or Gymnomitrion concinnatum; w Greenland; Alaska,
Maine, Tenn.; Europe.
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