104 PLANTS WRIGHTIAN^. V. 



317. IvA DEALBATA (sp. nov.) : hei'bacea, cano-tomentosa ; foliis alternis cuneato- 

 oblongis 3 - 5-fidis vel laciniato-pinnatifidis venosis, segmentis lanceolatis subiute- 

 gris acutis ; capitulis glabellis parvis in thyrsum terminalem angustum nudiuscu- 

 lum congestis ; involucre 5-phyllo, squamis orbiculatis mucronatis margine lato sca- 

 rioso villosi-ciliato cinctis ; floribus fcemineis 5 ; acheniis subglobosis. — In a moun- 

 tain valley, between the Limpia and the Rio Grande, New Mexico ; Sept. — Eoot 

 annual 1 Stems nearly simple, one or two feet high, clothed with a somewhat de- 

 ciduous implexed white wool, terete, leafy to the contracted and dense panicle. 

 Leaves two to four inches long, clothed with a fine and matted white wool, which 

 is more or less deciduous from the upper surface, very veiny, the older ones often 

 venulose-buUate, contracted into a short margined petiole, or subsessile ; some of the 

 lower, undivided and sparingly toothed ; the upper*, more triangular in outline and 

 pinnately parted, the lower lobes half an inch to an inch long, lanceolate or linear- 

 lanceolate. Heads subsessile, crowded, not canescent, in fruit barely a line wide. 

 Involucre uniserial. Corolla of the fertile flowers a very short truncate tube. 

 Achenia somewhat glandular, pyriform-globose. — The foliage and inflorescence 

 bring this plant near to Euphrosyne ; but there is no inner series of hyaline involu- 

 cral scales, as in that genus and Cyclachsena, and the achenia are globular. 



318. Ambrosia coronopifolia, Torr. 8f Gray, Fl. 2. p. 291. Fields at Presidio 

 de San Elisario ; Sept. — Fruit, as described in the Flora of North America, pretty 

 large, turgid, and entirely destitute of projecting points or tubercles.* 



X Franseria tenuifolia, var, tripinnatifida, Gray, PI. Lindh. 2. p. 227. 

 Ambrosia fruticosa (excl. /3.) & A. confertiflora, DC. I. c. A. longistylis ] Gray, 

 PL Fendl. p. 80. Western frontiers of Texas; coll. of 1851.^ — The specimens are 

 young, and less than a foot high, from an apparently perennial, thickish, but hardly 

 woody root. I think the stem is not really woody in Berlandier's specimens, on 

 which De Candolle's Ambrosia fruticosa is founded. Lindheimer has a taller form 

 of the species in his collection of 1851, from New Braunfels, with the stems four 

 or five feet high. The foliage varies much. The species is well distinguished by the 

 small fruit being armed all over with short and stout incurved and uncinate spines. 



319. F. TENUIFOLIA, var. lobis foliorum latioribus ssepius brevioribus. On 

 the Leona and Nueces ; June. — A coarser form, of which very few specimens were 

 gathered. 



320. F. HooKERiANA, Nutt. ; Torr. ^ Gray, Fl. 2. p. 294. Road-sides, valley 

 of the Rio Grande, New Mexico ; Oct. 



321. Hymenoclea monogtra, Torr. Sf Gray, PI. Fendl. p. 79, adnot. Banks of 

 a tributary of the Pecos ; Oct. — The stems of this curious plant are three or four 



* Ambrosia psilostachya, DC. Prodr. 5. p. 526, is the same as No. 429 and 430 of Lindheimer's Texan 

 collection (A. Lindheimeriana and A. glandulosa, Scheele), which, as the tubercles of the fruit were some- 

 times wanting or very obscure, I took for mere varieties of A. coronopifolia. They are perhaps suffi- 

 ciently distinct. 



De Candolle's specimen of A. integrifolia, from the Paris Garden, is A. bidentata. A. hispida, Pursh, 

 which I have seen in the Sherardian herbarium, is a plant which has not been detected since the time of 

 Catesby. 



