CATALOGUE. 239 



Ait, var. occidentalism, Watson (U. dioica, L., var. occidentalis, Watson, vol. 

 v, King's Report, p. 321), Utah. 



Urtica dioica, L. — Western New Mexico, Loevv. 



Urtica Breweri, Watson (Proc. Amer. Acad, x, p. 348). — Perennial, 

 erect, rather slender, spinulose ; leaves quite thin, very coarsely and some- 

 what irregularly toothed, 3-5' long, 1-1 £' wide, cuneate, rounded, or sub- 

 cordate at base; petioles slender, 1^-3' long; flowering panicles loose, 

 about as long as the petioles ; ovate achenium £' long, included in the 

 obovate, hispid perianth. Very variable. — Southern Colorado (71). — Plate 

 XXV. Natural size. Fig. 1. Staminate flower. Fig. 2. Pistillate flower. 

 Fig. 3. Achenium, enclosed by the large inner sepals. Fig. 4. Calyx 

 opened, showing mature achenium. All enlarged about 10 diameters. 



Humulus Lupulus, L. — Utah and Colorado (53). 



BETULACE^E. 



Betula occidentalis, Hook. — Northern Nevada, Utah, and Colo- 

 rado (841). 



Betula glandulosa, Michx. — Colorado (838, 839). 



Alnus incana, Willd., var. glauca, Ait. — Arizona, Utah, and Colo- 

 rado (840). 



Alnus oblongifolia, Torr. (in Bot. Mex. Bound, p. 204). — " Branches 

 smooth and shining ; leaves oblong-lanceolate, acute at each end, some- 

 what doubly serrate, smooth above and minutely pubescent beneath, with 

 surfaces green ; nutlets wingless. Tree 30° high. Leaves 2£-3£' long 

 and 1-1 y wide, unequally serrate, serratures glandular at the tip. Petiole 

 about one-third as long as the lamina. Catkins somewhat paniculate, ovate. 

 Nutlets orbicular-obovate, without any trace of a wing." I have not seen 

 the plant, and hence have quoted the above from Bot. Mex. Bound. 1. c. — 



Arizona. 



PLATANE^E. 



Platanus racemosa, Nutt. — Leaves broadly cordate, deeply 5-cleft, 

 divisions sharp pointed, lanceolate, the lower smaller, sometimes only 

 3-cleft from suppression of the lowest lobes. Upper surface at first covered 

 with branching, yellow hairs ; under surface always whitish woolly ; fertile 



