436 CONTEIBUTIONS FROM THE NATIONAL HERBARIUM. 



2. Acrolasia parviflora Heller, Muhlenbergia 1: 138. 1906. 



Mentzelia parviflora Heller, Bull. Torrey Club 25: 199. 1898. 



Type locality: Eleven miles southwest of Santa Fe, New Mexico, on the road 

 leading to Canyoneito. Type collected by Heller (no. 3750). 



Range: New Mexico and Arizona. 



New Mexico: Near Santa Fe; Organ Mountains; Cliff; Hillsboro; near Rio Apache; 

 Wheelers Ranch; Sandia Mountains. Plains and foothills, in the Upper Sonoran Zone. 



The plants from the southwestern part of the State have the cauline leaves mostly 

 linear-lanceolate and entire, with only occasionally a toothed one. The species is 

 close to Acrolasia albicaulis. 



4. MENTZELIA L. 



Herbaceous annuals or perennials with alternate, simple, coarsely toothed or lobed 

 leaves having short petioles, and solitary sessile axillary orange-colored flowers; 

 younger stems, leaves, and capsules covered with stiff barbed white hairs; flowers of 

 medium size; petals and sepals 5; filaments not dilated; fruit clavate-cylindric, with 

 a few ellipsoid or pyriform seeds, these finely striate in curved lines. 



key to the species 



Annual; leaves acute or acuminate; seeds several; capsules thin- 

 walled 1. M. asperula. 



Perennial with tuberous root ; leaves acute or obtuse ; seeds solitary; 



capsules thick-walled and woody 2. M. monosperma. 



1. Mentzelia asperula Woot. & Standi. Contr. U. S. Nat. Herb. 16: 148. 1913. 

 Type locality: Trujillo Creek, Sierra County, New Mexico. Type collected by 



Metcalfe (no. 1364). 



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



New Mexico: Trujillo Creek; Organ Mountains. Canyons, in the Upper Sonoran 

 Zone. 



2. Mentzelia monosperma Woot. & Standi. Contr. U. S. Nat. Herb. 16: 149. 1913. 

 Type locality: Organ Mountains, New Mexico. Type collected by Woo ton, 



August 29, 1894. 



Range: Southern New Mexico. 



New Mexico: Organ Mountains; 35 miles west of Roswell. Dry hills, in the Upper 

 Sonoran Zone. 



97. CACTACEAE. Cactus Family. 



Green fleshy-stemmed spiny perennials, mostly leafless xerophytes of peculiar 

 aspect; stems globose, cylindric, or flattened, tuberculate or ridged, often jointed, 

 the spines and spicules borne on restricted areas known as areoles; flowers mostly 

 large and handsome; sepals numerous, in several series, gradually becoming petaloid; 

 petals numerous, of delicate texture and handsome colors; stamens very numerous; 

 ovary inferior, with a thick style and several stigmas; fruit a dry or pulpy berry 

 with thin or thickened rind and numerous seeds in the single cell. 



KEY TO THE GENERA. 



Plants with small terete caducous leaves; stems jointed; 



spines often barbed, accompanied by glochids; 



tube of the flowers short 1. Opuntia (p. 437). 



Plants without leaves; stems not jointed; spines not 



barbed, without glochids; tube of flowers more or 



less elongated. 



