408 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



7. Schmaltzia bakeri Greene, Leaflets 1: 132. 1905. 



Type locality: Near Fort Collins, Colorado. 



Range: Colorado to New Mexico and Arizona. 



New Mexico: West of Santa Fe; Tierra Amarilla; Sierra Grande; Farmington; 

 Carrizo Mountains; Chama; Reserve; Fort Bayard; Silver City. Low bills, in the 

 Upper Sonoran Zone. 



2. RHOEIDIUM Greene. 



Stiff, woody, widely branching desert shrub, often 2 meters high and of equal 

 diameter, with stems intricately interlaced, the short ones sometimes spinescent; 

 leaves generally about 2 cm. long, with about 7 elliptic leaflets borne on a winged 

 rachis; leaflets acute, mostly entire; flowers small, in crowded clusters on the naked 

 branches of the previous season in the axils above the leaf scars; calyx lobes orbicu- 

 lar, concave, entire; petals white, finely ciliate; fruit globose, about 6 mm. in diam- 

 eter, hispidulous, viscid. 



This genus is very close to Schmaltzia, as here understood, the differences in the 

 leaves and the color of the flowers being hardly sufficient for separation. The descrip- 

 tion of the fruit of Rhoeidium given by Doctor Greene is not correct for the fruit 

 of the species in New Mexico. It is always orange scarlet, nearly like that of Schmalt- 

 zia. The plant is also strikingly like the species of that genus in general habit, instead 

 of being very diverse, as has been suggested, and the two grow side by side. 



1. Rhoeidium microphyllum (Engelm.) Greene, Leaflets 1: 143. 1905. 



Rhus microphylla Engelm. in A. Gray, PI. Wright. 1: 31. 1852. 



Type locality: "Margins of thickets, on the top of hills, in the large prairie be- 

 tween New Braunfels and San Antonio," Texas. 



Range: Western Texas to southern Arizona, south into Mexico. 



New Mexico: Socorro; Berendo Creek; Hachita; Tortugas Mountain; Hopkins 

 Mill; Organ Mountains. Dry hills, in the Lower Sonoran Zone. 



3. TOXICODENDRON Mill. Poison oak. 



Low shrubs, usually less than 1 meter high, with 3-foliolate poisonous leaves having 

 large, broadly ovate to rhombic, acuminate, coarsely few-toothed or entire leaflets; 

 flowers inconspicuous, greenish yellow, in small seVeral-flowered axillary panicles; 

 fruit depressed-globose, glabrous, thin-walled, white and shining when mature. 



1. Toxicodendron rydbergii (Small) Greene, Leaflets 1: 117. 1905. 



Rhus rydbergii Small in Rydb. Mem. N. Y. Bot. Gard. 1: 268. 1900. 



Toxicodendron punctatum Greene, Leaflets 1: 125. 1905. 



Type locality: Not definitely stated, apparently Montana. 



Range: British Columbia and Montana to Nebraska and New Mexico. 



New Mexico: Winsors Ranch; Black Range; Sandia Mountains; Mogollon Moun- 

 tains; White Mountains. In woods, in the Transition Zone. 



In New Mexico the plant goes under the name of "poison oak," but in other parts 

 of the United States the name given is more often "poison ivy," which would seem 

 much more appropriate. The type of T. punctatum came from the Black Range 

 ( Metcalfe 1088). 



4. RHUS L. Sumac. 



Erect spreading shrubs 1 to 2 meters high or more, with pinnately 5 to many-foliolate 

 leaves and axillary or terminal panicles of small, dull whitish or yellowish flowers; 

 leaves persistent or deciduous, the leaflets large, 3 to 8 cm. long; flowers and fruit as 

 described under the family. 



