436 CONTRIBUTIONS 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 Canyoncito. Type collected by Heller (no. 3750). 
Rance: 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....... wee eee eee ee ence ee cence eee eeeeeee 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. & Standl. Contr. U. S. Nat. Herb. 16: 148. 1913. 
TYPE LocaLity: Trujillo Creek, Sierra County, New Mexico. Type collected by 
Metcalfe (no. 1364). 
Rance: Western Texas to southern Arizona, south into Mexico. 
New Mexico: Trujillo Creek; Organ Mountains. Canyons, in the Upper Sonoran 
Zone, 
2. Mentzelia monosperma Woot. & Standl. Contr. U. 8. Nat. Herb. 16: 149. 1913. 
TYPE Locaity: Organ Mountains, New Mexico. Type collected by Wooton, 
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. 
