BFNA Title: Nowellia
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.