﻿of North America. 7 



•view that the " tubers " were here mostly Nostoc colonies is sup- 

 ported by examination of a detached fragment enclosed in a small 

 separate wrapper in the pocket containing the type material 

 (Herb. Pearson). This scrap of the thallus contains several con- 

 spicuous 'protuberant globose Nostoc masses, but nothing in the 

 nature of true tuberous thickening, In other portions of the type 

 specimen, however, somewhat rounded glandular-thickenings, 

 furnished beneath with root-hairs, occur, though rarely. 



2. Anthoceros Carolinianus Michx. Fl. Bor- Am. 2 : 280. 1803. 



Anthoceros laciniatas Schwein. Spec. Fl. Am. Sept. Crypt. 25. 



1 82 1. 



Anthoceros laevis tenuis Nees {p. p.) Naturg. Eur. Leberm. 



4: 330. 1838. 



Anthoceros laevis major Aust. Hep. Bor-Am. no. 123". 1873. 



Thallus large, thin, ecostate, nearly smooth, prostrate, the mar- 

 gin often undulate-crisped and ascending, sometimes crowded and 

 subcaespitose, light- or dark-green, a little pellucid or, on drying, 

 opaque with a somewhat fatty lustre, dissected ; major segments 

 oblong or obovate, 1-3 times subdichotomously branched, 8-30 

 X2-7 mm., more or less widened at the rounded crenate apex, 4-8 

 cells thick in the middle, passing gradually into a wide 3- or 2- 

 stratose margin, or nearly uniform throughout; surface-cells dis- 

 tinct in terrestrial forms, obscure in the aquatic, irregularly 

 rhombic, becoming elongate-hexagonal, 20-1 20 X 18-30 /*: monoi- 

 cous: involucres sometimes united in pairs, thick-walled, some- 

 what pellucid, long-cylindrical, 2-5 X .5— 1.1 mm., sometimes con- 

 tracted or now a little widened toward the thin, subentire or 

 repand-dentate, rarely scarious mouth, often longitudinally plicate 

 toward the base : capsule slender, 25-50 X .25-. 5 mm., pale 

 brown, short-pedicellate, the valves twisted ; spores and elaters as 

 in A. laevis. 



Exsicc. Hep. Bor-Am. \2f\ Hep. Am. 164. 



On wet, gravelly ground and beside brooks, often nearly or 

 wholly submerged. Found especially in the Southern States. 

 Florida (Torrey, Austin, J. D. Smith, Underwood, Lighthipe, F. C. 

 Straub); Georgia (Lesquereux) ; South Carolina (Ravenel) ; North 

 Carolina (Schweinitz). What was undoubtedly this species came 

 into the hands of Dillenius from Virginia, where it was collected 

 by Mitchell. Sterile plants in the Austin collection from Closter, 

 N. J. (Austin), and New Haven, Conn. (D. C. Eaton), seem also to 



belong here. 



