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BFNA Title: Nowellia
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XX. NOWELLIA Mitt.,
Nat. Hist. Azores, 321. 1870 * [For John Nowell,
1802--1867, of Todmorden, a Lancashire cotton
operative, contributor to Flora of Yorkshire] Richard H. Zander Plants in thin mats, green
with red, purple or reddish brown tints.
Stem hyalodermis present;
ventral-intercalary branching common but
Frullania-type
(lateral-terminal) branching rare; stolons absent. Rhizoids long, scattered, transparent. Leaves transversely very narrowly inserted or slightly succubous,
not decurrent, concave, usually distant, 2-lobed with lobes ending in a fine
acumen, leaf below lobes saclike; oil bodies absent. Underleaves
absent. Specialized asexual reproduction by gemmae, rare, 1-celled,
spherical to ellipsoidal, at shoot apex.
Sexual condition dioicous or
monoicous, often with autoicous or paroicous intermixed plants. Androecia
apical on a short ventral branch or intercalary, 3--10(--20) pairs of
imbricate bracts, each bract saccate, 2-lobed, dorsal lobe margin sometimes
toothed; antheridium 1 per bract, stalk 2-seriate. Gynoecia
terminal on short ventral branch. bracteole
similar to bracts; perianth narrowly ovate to elliptic, trigonous,
unistratose, mouth laciniate or spinose-dentate. Sporophyte capsule ellipsoidal, capsule wall 2-stratose; elaters
2-spiral. Species 8--10 (1
species in the flora): North America, Central America, South America, West
Indies, Eurasia, Atlantic Islands, Pacific Islands, Australia. The genus Nowellia is nearly cosmopolitan but, unlike
most of the other Cephaloziaceae, is mainly
tropical and subtropical. Only one species ranges into the North Temperate
Zone. SELECTED
REFERENCES Grolle , R. 1968. Monographie
der Gattung Nowellia. J. Hattori Bot. Lab. 31: 20--49. Robinson, H. A. 1970. Notes on the genus Nowellia. Bryologist
73: 150--152. 1. Nowellia curvifolia (Dicks.) Mitt., Nat. Hist.
Azores, 321. 1870 Jungermannia curvifolia Dicks., Fasc. Pl. Crypt. Brit. 2: 15. 1790 Plants prostrate, 1--2
cm. Stems 90--100 /um in diameter, 6--8 cells in width. Leaves
oblong, slightly overlapping, lobes asymmetrical, sinus broadly rounded,
deeply concave, 500--700 x 300--400 /um; lobed ca. 0.5 leaf length, lobe apices abruptly and
narrowly acuminate, cuticle mostly smooth.
Leaf cells medially
20--25(--30) x 13--17 /um, rounded-hexagonal; trigones absent but cell corner
walls often somewhat thickened. Underleaves absent. Specialized
asexual reproduction rare, by one-celled gemmae borne at plant apex on
leaf lobes. Androecial bracts in several pairs, saccate, 2-lobed, often marginally
denticulate. Gynoecial bracts 2-lobed, ca. 1 x 0.5 mm, marginally strongly
dentate, apically sharply acute. Perianth elongate, 2--2.5 x 0.5--0.6
mm, mouth not or weakly narrowed, spinose-ciliate. Sporophyte capsule longitudinal walls
with nodular thickenings. Elaters
9--11 /um in diameter. Spores 8--10 /um. Xylicolous, a
pioneer on decorticated logs, occasionally on sandstone or moist soil; N.B.,
Nfld. and Labrador (Nfld. & Labr.), N.S.,
Ont., P.E.I., Que.,; Ala., Ark., Conn., Del., D.C., Ga., Ill., Ind.,
Iowa, Ky., Maine, Md., Mass., Mich., Minn., Mo., N.H., N.J., N.Y., N.C.,
Ohio, Pa., S.C., Tenn., Vt., Va., W.Va., Wis.; Mexico; West Indies; Central
America (Guatemala, Honduras, Costa Rica); South America; Europe; Asia;
Atlantic Islands (Azores, Madeira). Nowellia curvifolia is easily recognized in the field by its distant leaves
with strongly inflated bases, the leaves often vineous
in color, with a narrow base, distal lamina bilobed with each lobe ending in
a long acumen of uniseriate cells, the basal leaf margins closely incurved to
form an open sac, and the perianths often present, distinctly three-angled.
The habitat is distinctive, generally restricted to decorticated fallen logs,
where it may be monocultural or mixed with other
liverworts. It is absent in the western portion of the flora area, but
commonly encountered in forests of the East. The androecial bracts are often
1--2 dentate laterally on the lobes. |
