SUNFLOWER FAMILY 147 
hirsute, regular, nies short pagep pedicel, strongly 3-nerved on one side; apn pistillate 
invo ~ cre os mm ted with an acute beak, several-ribbed, the ribs icin in acute tubercles 
soil, mat and w suse in the Pacific States occurring occasionally as a — in Washing. 
= and California, pha wae Govinand througho ut the United States and Canada. Type locality: “Virginia, 
anada uly— 
2. panbtpert artemisiifélia L. Annual Ragwood. Fig. 5217. 
Ambrosia elatior L. Sp. 987. 1753. 
Ambrosia artemistifolia - op. cit. 988. 
Ambrosia artemisiifolia diversifolia Piper, Contr. U.S. Nat. Herb. 11: 551. 1906. 
Ambrosia elatior var. artemistifolia Farwell, Rep. Mich. Acad. 15: 1 
nching annual tn dm. high, the stem slender, scsi stri —e = incurved-pubescent, 
sometimes Basic ges -hirsu Tiaves opposite below, alternate above, triangular or ovate in out- 
= wly ihe ae petioles 1-5 cm. long, the blades 12-pinnatifd with often toothed 
d, ia acute divisions, rather thin, pubescent like the stem, paler and more densely 
ne es Sunes the uppermost leaves often linear and entire; staminate heads in terminal, often 
3 mm. in diameter ut 12—32-flo i 
ac u 
the upper axils or at the base of staminate racemes, subtended by reduced leaves and a few small 
herbaceous bracts; fruit turgid-obovoid, 3-3.8 mm. long Ne panear ng beak, this 0.7-1.2 mm. long), 
pubescent : gla ndular, bearing aie apex ” body 1 -7 usually acute, short, conic a Tee Hy 
ey una 
abu ms nt weed nearly throughout the United States and southern Canada south into tro ical America, 
occasional in our ee (Washington to California); also naturalized in Europe. Type locality: irginia, Pik 
sylva * Jun t 
5214. Hymenoclea pentalepis 5216. Ambrosia trifida 
5215. Hymenoclea monogyra 5217. Ambrosia artemisiifolia 
