STUDIES IN THE GENUS BIDENS. I 
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 180 
EARL E. SHERFF 
In the prosecution of taxonomic researches upon the different 
species of Bidens, the writer has found several species either 
apparently undescribed heretofore or bearing names no longer 
tenable. This article will deal mainly with some of these cases. A 
list of the various herbaria and libraries consulted thus far, and of 
the several botanists who have kindly rendered assistance in this 
work, will be deferred until a later time. 
Bidens Deamii, sp. nov.—Herba annua, plus minusve pallida, 
3 dm. alta, caule profunde ramoso; ramis subglabris, subtetragonis, 
striatis, inferioribus arcuato-adscendentibus, ramulis monocepha- 
licis. Folia opposita, petiolata, petiolo adjecto 1-2 cm. longa, 
tri-(aut pinnati-)partita, subglabra; foliolis terminalibus trilobatis, 
cuneatis; foliolis lateralibus integris aut dentatis; dentibus et 
lobis submucronatis, integris. Petioli 3-8 mm. longi, submarginat, 
oe a ee —— terminalia, longe pedunculata, subcorym- 
bosa, } dentibus aut erectis, 1. 5-2 cm. lata, ligulata. 
Involucrum basi hispidum; squamis duplici serie dispositis; 
exterioribus linearibus, subviridibus, ciliatis; interioribus paulo 
longioribus, lanceolatis, margine diaphanis. Ligulae albae aut 
subroseae, striatae, 8-12 mm. longae. Achaenia linearia, sulcata, 
spinulosa, biaristata aristis retrorsum hamosis, nigra aut versus 
apicem fusca, interiora demum plus minusve attenuato-rostrata 
et 1.2 cm. longa. 
Chas. C. Deam, Cholula, Mexico, January 1, 1899 (type in Herb. Field 
Mus.); Rose, Standley, and Russell 13405, in vicinity of San Blas, Sinaloa, 
Mexico, March 24, 1910. 
A species approaching, in its sometimes slightly beaked achenes, the genus 
. Cosmos, but otherwise showing stronger affinities with Bidens. 

Bidens parvulifolia, sp. nov.—Herba caule adscendente- aut 
plus minusve repente, subsimplice, longo 1.5 dm. plusve, subp nner 
aut subglabro, tetragono. Folia opposita, petiolata, ovata, acuta 
Botanical Gazette, vol. 56] le 
