1915} Fernald & St. John,— Species and Varieties of Bidens 25 
IsLaAND: sandy pond-margins, east of Dickens Point, Block Island, 
September 15, 1913, Fernald, Long & Torrey, no. 10,688 (TYPE in Gray 
Herbarium). 
Bidens cernua L. as it occurs in eastern America is highly variable 
and especially so in its foliage. Besides the typical form of the species 
with elongate-lanceolate or linear-lanceolate leaves with many coarse | 
serrations, we get the dwarf bog plant, var. minima (Huds.) DC., 
with tiny, spatulate or oblanceolate petioled leaves and usually solitary 
campanulate heads; and the very large varieties with broader copi- 
ously serrate leaves, varieties elliptica and integra of Wiegand. On 
the brackish sands of the Magdalen Islands and Prince Edward Island 
occurs a depressed or matted, freely branching plant with the heads - 
and achenes and the hispid stems of B. cernua. The small, fleshy 
leaves, however, are mostly obtuse and with few and obscure denta- 
tions, and the outer fleshy bracts of the involucre are oblong or broadly 
oblanceolate and much exceeding the inner series. This little plant, 
though first noted in maritime sands, does not seem to be restricted 
to brackish habitats, for identical material has been collected on the 
sandy shore of a pond in Coés County, New Hampshire, and an old 
specimen of Gray’s from western New York is probably not separable. 
This extreme variation may be called 
RNUA L., var. oligodonta humili i depressa . 
2 dm. 
angustatis "inne vel —_ dentatis, dentibus seus 5 
obtusis, foliis apie 2-5 ¢ oF oer 0.5-1.5 cm. latis; capitulis 
John, no. 8208 (TYPE in Gray Herbari nie "Epwanp 
LAND: wet brackish sand, No ake, be County , pint ag 
1912, Fernald, Long & St. John, no. New 
sandy shore, Success Pond, Coos Cou ak, angie 27, 1907, A. rig 
Pease, no. 10,738. Nrw Vorx: western section, Gray. 
