250 COMPOSITE. Ambrosia. 



A. hlispida, Pursh. Perennial, spreading from a suffrntescent base, strigose-hispidulous or 

 liis])icl and liirsute : leaves all petioled, twice and thrice pinuatifid or interruptedly pinnately 

 divided into numerous short and small oblong ultimate lobes : sterile raceme commonly 

 solitary and elongated : fruit with a stout short beak and commonly 4 short acute tubercles. 

 — Fl. ii. 743, the original in herb. Hherard was probably from Bahamas. A. critlimifulia, 

 DC. Prodr. v. 525; Torr. & Gray, 1. c. — Sandy sea-shore, Florida. (W. Ind.) 



A. psilostacliya, DC Perennial from slender running rootstocks, stouter tlian A. artemi- 

 aid folia, '2 to G feet high, with strigose and sonic loose hirsute pubescence: leaves thickish; 

 upper simplv and lower twice pinnatifid ; tlie lobes mo.stly lanceolate and acute : sterile 

 heads commonly short-pedicelled : fruit mostly solitary in the axils below, turgid-obovoid, 

 less than 2 lines long, rugose-reticulated, obtusely short-pointed, either wholly unarmed or 

 (sometimes on the same ])lant) with four short either blunt or acute tubercles. — Prodr. v. 

 526; Gray, PI. Wright, ii. 86, & Bot. Calif, i. 344. A. Peruviana, UC. 1. c., as to pi. Mex., 

 hardly of Willd. A. coronopifolia, Torr. & Gray, Fl. ii. 291. A. Lindheimeriuna & A. r/ltin- 

 dulosa, Scheele in Linn. xxii. 156, 158. — Moi.st prairies and beds of streams, Illinois and 

 Saskatchewan to Texas, Arizona, and California. (Mex.) 



A. pumila, Gr.vy. Perennial, a span or two high from slender running rootstocks, canes- 

 cent throughout with a dense and close silky pubescence, very leafy : leaves nearly all alter- 

 nate and long-petioled, 2-3-pinnately parted into linear-oblong crowded lobes : sterile heads 

 in a short spike : fruit obovoid, pubescent, muticous, a line long (rarely two are connate at 

 liase). — Proc. Am. Acad. xvii. 217. Franseria pumila, Nutt. Trans. Am. Phil. Soc. 1. c. 

 344; Grav, Bot. Calif, i. 345, ii. 615. Hemiambrosia, Delpino, Stud. Comp. vVrtemis. 57. — 

 San Diego, California, Nuttall, &c., recently coll. by Cleveland in fruit. 



82. FRANSERIA, Cav. {A7it. Franser, a physician and botanist in 

 Madrid in tlie time of (.'avanilles.) — Herbs or shrubby phmts (all American) ; 

 with chiefly alternate leaves, some species with habit of Amhrosia and near it in 

 character, others with the fruiting involucre nearly that of Xanthiurn. — Cav. Ic. 

 ii. 78, t. 200 ; Willd. Hort. Berol. i. t. 2 ; DC. Prodr. v. 224 ; Torr. & Gray, 

 Fl. ii. 292. Franseria, Hemixanthidium, & Xanthidlum, Delpino, Stud. Comp. 

 Artemis. 58-G7. 



§ 1. Spines of the fruiting and 1-2-flowered involucre comparatively few, con- 

 ical, subulate, or flattened with the inner face more or less concave, usually 

 straight or merely incurved. — § Acantholcena., DC. 



* Herbaceous perennial: fruiting involucre t^eldom over a line long, in the i^anic plant bearing 

 either one or two flowers. 



F. tenuifolia, Gray. Erect, 1 to 5 feet high, leafy to the top, hispid, variou.sly pubescent, 

 or glabrate : leaves mostly 2-3-pinnately parted or dissected into narrowly oblong or linear 

 lobes, and the narrow jjrimary rhachis often with some interposed small lobes, tlie terminal 

 elongated : sterile racemes commonly elongated and paniculate : fertile heads in numerous 

 glomerules below, in fruit minutely glandular, usually 2-flowered, obovate with narrow 

 obpyramidal base, armed with 6 to 18 short and stout incurving spines, their tips almost 

 always hooked, and an excavated cartilaginou.sly bordered areola above each. (Larger 

 leave's often 5 indies long or more.) — PI. Fendl. 80, PI. Wright, i. 104 (var. tripinna- 

 Ufida), Bot. Mex. BouthI. 87, & Bot. Calif, i. 346. Amhrosia lonfjistj/lis. Gray, PI. Fendl. 79, 

 as to no. 407, perhaps of Kutt. Ambrosia tenuifolia, Spreng. Syst. iii. 851 ? A. confcrti flora 

 & A. fruficosa (excl. var.), DC. Prodr. v. 525, 526. Xanthidium tenui/olium, Delpino, 1. c. 

 62. — Moist grounds, from Texas to N. Colorado, S. California, and southward. (Mex., 

 Hawaii, &c.) 



* * Herbaceous, with fruiting invohicre 3 or 4 lines long at maturity, and longer stout or broad 

 spines : stems low. 



F. Hookeriana, Ni;tt. Diffusely spreading from an annual (or perennial?) root, freely 

 liranched, hirsute-pubescent or hispid, sometimes canesccut with strigose-sericeous pubes- 

 cence when young : leaves of ovate or roundish circumscription (1 to 3 inches broad) and 

 bipinuatifid, or tlie upper oljlong and pinnatifid: sterile racemes solitary or paniculate : fruit- 



