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1902] ROCKY MOUNTAIN PLANTS 369 



has also Oe?iothcra JoJmsojii Parry, Am. Naturalist 9: 270. Jones 

 suggests the possibility that the species he describes is 0. Jolm- 

 soni, but at the same time points out characters that unmistakably 

 distinguish the two. While the description of 0, Johnsoni is 

 very meager, yet in so essential a matter as the character of the 

 capsule it is very explicit. Certainly no observer, least of all 

 Parry, would have compared a large perennial such as Lavauxia 

 Hozvardi with the small annual Lavauxia priminervis (Gray) 

 Small, which has a capsule similar to that attributed to 0. Johnsoni. 

 The species to which Lavauxia Hozvardi is closely allied is Z. 

 brachycarpa (Gray) Britton Mem. Torr, Club 5: 235; Oenothera 

 brachycarpa Gray, PI, Wright i : 70, and Coulter, Contrib. U. S. 

 Nat. Herb. 2: 116; but here again the character of the capsule 

 serves to distinguish these two. In the latter it \^ smooth and 

 acute, with narrow wings ; while in the former it is larger, oblong- 

 obtuse, broadly winged, and cinereous pubescent. The leaves 

 also are all oblanceolate, tapering into the petiole, from entire to 

 coarsely and irregularly toothed, therefore the lamina continuous 

 and not distinguished into lateral and terminal lobes. 



The species occurs on arid denudated hills from northern 

 Colorado through Utah to Nevada. 



COLORADO AND W^YOMIXG THORxNS. 



Crataegus Wheeleri, n. sp. — Probably a small shrub, the 

 branches slender and virgate : leaves narrowly oblong to elliptic, 

 3-5^"^ long, 1^2^"^ broad, from acute to obtusely rounded at 

 apex, cuneately tapering at base to a slender petiole one-fourth 

 to one-half as long as the blade, the shallow crenate serratures 

 wanting on the cuneate base, light green and glabrous below, 

 brighter green but obscurely and sparsely appressed strigulose 

 above, firmer in texture and somewhat glossy above at maturity : 

 spines slender, flexible, glossy black, 2-3*=^ long: flowers small, 

 12-14^111 bi-Q^d, on slender glabrous pedicels, in close few- 

 flowered corymbs; calyx-tube obconic, glabrous; calyx-lobes 

 small, triangular, at length reflexed : petals suborbicular, about 

 ^mm -^ diameter: stamens 20 \ anthers yellowish-white: pistils 5 :^ 

 •fruit small, sub-globose, 6-8"^^ in diameter, purplish-black (in 

 dried specimens), in few-fruited suberect clusters; flesh seem- 



