306 PLANTS NOV^ THURBERIAN^. 



the road, and had already been gathered at the same place by the late Dr. Gregg ; a 

 truly shrubby Argemone, which was found only with mature fruit ; and a new Acacia, 

 so far as can be judged from the flowers, with remarkably thick and coriaceous leaves. 

 The two latter were met with only in the mountain pass of La Pena, near the town of 

 Parras." (G. Thurber.) 



NEW GENERA AND SPECIES. 



Ranunculus hydrocharoides (sp. nov.) : glaberrimus ; caulibus floriferis erectis 

 (spithamaeis) foliosis stolonibusque repentibus validis ; foliis longe petiolatis integerri- 

 mis orbiculari-cordatis ovato-rotundis ovalibusque, caulinis sensim oblongis basi at- 

 tenuatis seu spathulatis ; petiolis basi scarioso-dilatatis ; pedunculis oppositifoliis uni- 

 floris folio paullo brevioribus ; petalis 5-8 obovatis (luteis) sepala subduplo superan- 

 tibus glandula semilunari crassa instructis ; carpellis pauciusculis Isevibus stylo brevis- 

 simo apiculatis in capitulum subglobosum acervatis. — In wet marshes, Mabibi, Sonora ; 

 June. Perennial. Stems, and also the long stolons, stout, striate, fistulose. Leaves 

 rather fleshy, diverse in shape, the lowest usually rounded and more or less heart- 

 shaped, 6 to 15 lines long ; the larger cauline li inch long, these gradually becoming 

 narrower and tapering into the long petiole. Sepals orbicular. Petals 2i to 3 lines 

 long, obtuse, tapering into a conspicuous broad claw, at the summit of which a thick- 

 ened gland, with a small sinus above it, takes the place of the ordinary scale. Sta- 

 mens 20 or more. Carpels 15 to 20, in a globular head of only 2 lines in diameter. — 

 This belongs to the same group, apparently, with R. salsuginosus, Cymbalaria, &c., 

 but is very different from any described species. 



Argemone fruticosa (sp. nov. Thurber, in litt.): glaberrima, valde glauca ; ramis 

 patentibus lignosis undique foliosis inermibus ; foliis crassis oblongis sinuatis margine 

 spinosis ; floribus inter folia sessilibus ; capsula ovata echinato-spinosa. — In the 

 mountain pass of La Pena, Cohahuila; November, 1852; in fruit. — Hazardous as it 

 always is to propose new species of Argemone, especially upon incomplete materials, 

 yet there would seem to be little room for doubt in respect to this plant ; which forms 

 a stunted shrub, of \\ to 2| feet in height, with its rigid and divergent branches woody 

 almost to the growing tips, the older ones squarrose with the crowded and salient 



