Iva.] COMPOSIT.E. 309 



25. AMBROSIA. Linn, 



Capitula homogama, monoica; fceminea uniflora, involucro inermi (vel spinoso) cmcta; 

 mascula multiflora, rachide ebracteokta. Achenium globosum. — Fruticcs vel Herbse Asim 

 vel EuropcB indigence, foliis alternis^ inferioribus nonnunquam oppositis, integris ant sapius 

 divisis; capitulis spicatis, spica linearis siiperne mascula^ basi lohata etfcenmiea; involucns 

 capituli masculi uniserialihus^ gamophyllis. Less, 



1. A. elatior; foliis bipinnatifidisglabriusculis, petiolislongeciliatis, racemis terminalibus 

 pauiculatis, caule virgato. Willd.— Linn.— Pur sh, FL Am, v. 2. />. 581. Elliott, Carol, v, , 

 2. p. 477. 



Hab. Canada. Pitrsh, 



2. A, paniculata ; pilosa, foliis bipinnatifidis summis pinnatifidisj racemis terminalibus, 

 fructibus supra medium spinis brevibus erectiusculis. — Miclu Am. v. 2. p. 183. Pnrsh, Fl. 

 Am. V. 2. p. 581. Elliott, Carol, v. 2. p. 478, 



Hab. Canada. Pursh. Lake Huron. Dr. Todd. Straits of de Fuca, and Nutka, Nortli-Wcst America. 

 Dr. Scouler. 



3. A. acanthicarpa ; setis asperis rigidis hispida valde ramosa, foliis bipinnatifidis seg- 

 mentis linearibus, racemis terminalibus, fructibus spinis rigidis subulatis longis patcntibus 

 undique tectis. 



Hab. Banks of tke Saskatcliawau and Red River. Douglas. Drummond. Plentiful on the sandy 

 banks of the Columbia, near Indian Villages and Camps, and at the Grand Rapids. Douglas.—Thft sin^larly 

 spinescent fruit of this species, distlnj^uishes it from every other with which I am acquainted. 



26. IV A. Linn. 



Capitula hetevogama, Jloribns foemineis uniserialibus in ambitu, reliquis mascuUs. Ach- 

 enium obcompressum. Cor. ? tubulosa s. campanulata. Rachis bracteolata.— Herbse vel 

 Frutices Americanm; Mils alternis sen oppositis, trinerviis ; cayiixxWs spicatis (mine axillari- 

 bus), spica terminali soUtaria lineari basi fasminea, superne mascula; involucris oUgophyllis, 

 uniserialibus. Less. 



L /. axillaris; herbacea, foliis subcarnosis lanceolatis obtusis bjisi attenuatis integerrimis 

 pilosis V. glabris, capitulis solitariis axillaribus nutantibus. (Tab. CVll.)— 7^5^. Fl. Am. 

 V. 2. p. 743.-/5. robustior; omnibus partibus majoribus. 



J?arfi:r annua, parva. Caulis erectus, plerumque valde ramosus; ram/ erecti, ang^ulati, glabri, vel pilosi. 

 Folia altema, rarius opposita, subunciam longa. lanceolata, ma-Is minusve lata, basi attcnuati, subcarnosa, 

 rigidiuscula, obtusa, integerrima, -labra vel piloso-scabra, uninervia. Capitula solitaria, axlllaria, brevissime 

 pedunculata, nutantia. Involucrum subhirsutnm, e foliolis 4-5 in unicum hemisphiericum lobatum coahtis. 

 Floscidi inclusi, rcoeptaculum paleaceum, paleis linearibus sursum latioribus ciliatis : Masc. plunmi, centralis. 

 Cor tubulosa, subinfundibuliformis, dentibus 5 reflexis. Anther<B exserta?, inappondiculat^. Pistillum 0. 

 Fm uniserialis in ambitu. Cor. brevis,tubuloso-fiUformis,5-dentata. Germed obovatum. %/ilineares,longi, 

 lati. Achenium late obovatum, epapposura, pubescens, nigro-fuscum, corolla pcrsisteutc brevi coronatum. 



Hab Between Carlton House and Edmonton House, on the Saskatchawan. fi. Common on the 

 barren grounds from the " Grand Rapids" of the Columbia, to the Rocky Mountains, in sandy dry soils. 

 Douglas -Mr. Drummond notices this plant as havin- the appearance of Glaux mar^tnna. If I am n-ht 

 in referrin- it to Tur^Vs Iva axillaris, it has probably an extensive ran-e. his plant being found, by Bradbury, 



