APRIL, 1919. XANTHIUM MILLSPAUGH AND SHERFF. 25 



Grace, Maryland, 2 sheets in Hb. Gray; Hb. Mo. 85399; A. S. Hitch- 

 cock, Iowa City, Iowa, without date, Hb. Mo. 85406) which, while 

 referable to X. chinense, showed a strong approach, in the subglobose 

 character of the fruits, to X. globosum. 



6. XANTHIUM ARCUATUM Millspaugh and Sherff, Field Mus. Bot. 4: 4. 



PI. 2. 1918. 



Caulis superne scabridus, 3-5 dm. altus. Folia deltoideo-ovata 

 3~5-lobata, dentata, basi cordata aut subtruncata, utrinque setulis 

 adpressis scabra, petiolis adjectis circ. i dm. longa, petiolis laminis 

 subaequantibus. Fructuum (PL VII., f. 6; PI. VIII., ff. 24-26) corpus 

 anguste ovatum, aculeis numerosis armatum, glandulis multis vestitum, 

 demum 1.3-1.5 cm. longum et 5-6 mm. crassum; rostris rectis aut 

 minime arcuatis, apice hamosis, non pubescentibus sed infra glandu- 

 los ferentibus, 3.5-5 mm. longis; aculeis tenuibus, maximam partem 

 arcuatis, plus minusve rubro-purpureo tinctis, apice hamosis, infra 

 glandulosis, 4-6 mm. longis. 



DISTRIBUTION: New York. 



SPECIMENS EXAMINED: NEW YORK: Chemung County, river shores 

 and low places, Oct. n, 1896, T. F. Lucy (Hb. Field 4953, type). 



A species with burs intermediate between those of X. chinense and 

 those of X. pennsylvanicum, but having prickles more arcuate. Our 

 failure to find, in various herbaria, additional material matching the 

 type would seem to indicate that either X. arcuatum is a very rare 

 species or that it will subsequently prove to be of hybrid origin. 



7. Xanthium curvescens sp. nov. PI. XI. 



Caulis ramosus, rubens, scaber, +3 dm. altus. Folia deltoideo- 

 cordata, infirme trilobata, margine dentata, scabrida, minute reticulata, 

 punctis glandulosis numerosis minimis punctata, setulis minutis adpres- 

 sis scabra, non crassa, petiolis adjectis +i dm. longa, petiolis laminas 

 subaequantibus. Fructuum (PI. VII., f. 7; PI. VIII., ff. 27-29) corpus 

 anguste cylindrico-fusiforme, rubro-badium, superne sensim angus- 

 tatum et in duo rostra distantia productum, exteriore facie 30-50 

 aculeis armatum, glabratum sed glandulis minutis numerosis punctatum 

 uti bases aculeorumet rostrorum; rostris et aculeis rectis solum inferne, 

 superne valde arcuato-uncinatis; rostris crassioribus et passim paulo 

 longioribus, inferne breviter hispidis; fructus corpore demum 1.3-1.6 

 cm. longo et 3.5-5 mm. crasso; aculeis 3-6 mm., maximam partem 

 4.5-5.5 mm. longis. 



DISTRIBUTION : Vermont. 



SPECIMENS EXAMINED: VERMONT: Orwell, Willard W. Eggleston 

 1420 (type in Hb. Gray). 



Because of its strongly bent prickles and beaks, we were disposed at 

 first to regard this species as a form of the European X. orientale L. 

 But in the many fruiting specimens of X. orientale examined from 



