SUNFLOWER FAMILY 153 
Many forms of this cosmopolitan weed are to be found and innumerable races have developed locally which 
have received specific ee ed the — sa involved he jog 7 hirano Rep. Spec. Baniend Magnan 20: 
1-221. 1923. The synonyms listed with the following taxa are those more frequently found in 
Xan thins bias Hira var. pikes? énse (Mill. ) -Forr; ri pe ; piers 2: 294. 1838. ‘Kanthium cana- 
dense Mill. Gard. Dict. = iB 1768; X, italicum Moretti, Senha tet Giorn fis. Chim. Dec. II. 5: 1822; 
X. saccharatum Wallr. ot. 12: 238. 1844; X. oviforme Wallr. op ag 240; X. campestre PPodilas Pittonia 
4: 99 Ae fc aro Tocsee op. cit. 63.) Burs usually 2-3(3. S) ¢ long, variable in shape and density 
4 prickl es, the beaks exceeding the prickles i in —_— the prickles more ro less densely hirsute toward the base 
well as s glandular. ~ cosmopolitan weed g in moist valleys and flood plains throughout the Pacific States 
Ty pe sala not know 
Xan m strumarium var. glabratum (DC.) nquist, Rhodora 47: 403. 1945. eee p pepo ct 
B glabr =~ DC. fod: 3% 523. 1836; X. Pennsyloanicum Wallr. Beitr. Bot. 17: 236. 1844; ? X. se 1gc e 
weootont Cockerel Proc. Biol. Soc. Wash. a a ; X. calvum Millsp. & — Field ae Bot. Sie 
pl. 9.) Burs usually 2-3 s shorter, variable in shape and density of Bo i Po 
ostly lacking the hirsute hairs 
lon 
ke exceeding the lene sam in Bet cay ‘the gk Ty eee clas toward the base and m 
of X. strumarium var. — ense. A cosmopolitan weed growing in moist valleys aaa flood plains throughout the 
Pacific States but more common from central California south. Type locality: ‘‘in Carolina.’ 
2. Xanthium spinédsum L. Spiny Clotbur. Fig. 5229. 
Xanthium spinosum L. Sp. Pl. 987. 1753. 
erect, branching annual up to 1 m. high, the leaf-axils armed with paired, papecct, 
ent 
afy 
si spines 3 cm. long or less, the stem whitish, strigillose or erectish pubescent. Leav 
ostly la henolatd or per ney we 5-12 cm lone including petiole, acuminate, cuneate at base, us zally 
acne fers few-lobed toward base, green above, ly canescent-strigillose beneath ; pistillate in- 
se 
volucres solitary or cnered in the axils and on pees lateral branches but not crowded, in fruit 
5226. ria ambrosioides strumarium 
Franseria 
5227. Franseria ilicifolia 
5228. Xanthium 
5229. Xanthium sp 
