CATALOGUE, 165 



woody caudex ; leaves petioled, opposite and alternate, roundish or broadly 

 ovate, 2-4" v^ide, few-toothed or nearly entire ; heads solitary at the ends of 

 nearly naked branches ; involucres 3" wide, the appressed scales obovate- 

 oblong ; rays 6-10, the oblong ligules much longer than the tube and shghtly 

 exceeding the disk, 2-toothed at the apex ; disk-flowers about 25 ; pappus 

 of a single bristle a little shorter than the disk-corolla. — The branches of the 

 style appear to be somewhat semi-cylindric rather than flattened. Crevices 

 of hmestone rocks on Stansbury Island, (Capt. Stansbury.) On the same 

 island, upon rocks; 4,500-5,000 feet elevation; June. (587.) 



IvA AXILLARIS, Pursh. Stems 6-15' high, much branched from a 

 somewhat woody slender base, very leafy ; leaves small, 9-12" long, 3-6" 

 wide, obovate or oblong, obtuse, narrowed at the base, minutely' appressed- 

 pubescent ; heads solitary in the axils of the upper leaves, nodding on short 

 peduncles; involucres of few concave orbicular foliaceous scales, either 

 distinct or partially united ; fertile flowers 4-5 ; chaif of the receptacle fili- 

 form-clavellate. — Saskatchewan to Oregon and California, and eastward to 

 Nebraska ; about Virginia City, Nevada, (Bloomer.) Abundant in the 

 Valleys, from the Truckee River to the Wahsatch ; 4-6,000 feet elevation ; 

 June-September. (588.) 



Ambrosia aetemisi^folia, L. North America from the Atlantic to 

 the Pacific, northward to the Saskatchewan and southward to Texas. 

 Humboldt Pass, Nevada ; 6,000 feet elevation ; September. (589.) 



Ambrosia psilostachya, DC. (A. coronopifolia, T. & G.) Illinois to 

 California, and southward to Texas ; Salt Lake Valley, (Stansbury.) Jordan 

 Valley ; 4,500 feet elevation ; August. (590.) 



Franseria^ Hookeriana, Nutt. Annual, much branched, 1-2° high ; 



the corolla tubular, more or leas enlarged at the throat, with four oyate spreading teeth. Scales of the 

 involucre in one or two series, ohlong, memhranaceous, keeled, one-nerved, the apex ciliate. Receptacle 

 naked, flat, foveolate. Anther-cells somewhat produced at the base. Style of the disk-flowers with 

 narrow flattened branches produced into a subulate hispid appendage. Achenia oblong, flattened, with 

 a single nerve at each margin. Pappus either none or of a single stout scabrous bristle, rather longer 

 than the achenium, or (in a doubtful species) of about 20 such bristles. — Low perennials, with many 

 stems rising from a stout woody caudex ; the leaves opposite or alternate, small, toothed or multifid, 

 punctate or dotted with resinous globules ; heads solitary or ia terminal corymbs, the flowers yellow. 

 Natives of Utah, New Mexico and Texas, or extending into Mexico. 



' FRANSERIA, Cavanili-ES. Heads of two sorts, the fertile ones at the base, and the sterile ones 

 composing the upper portion of the racemes or spikes. Fertile heads with an ovoid or oblong closed 

 involucre composed of numerous united scales, the tips free and spinescent or hooked ; corolla none or 

 rudimentary; style with filiform obtuse branches ; achenia oblong; pappus none. Sterile heads hemi- 

 spherical, the 12-20-flowered cup-shaped involucre of 8-12 united scales ; receptacle flattish, with filiform 

 chaff; corolla funnel-shaped, 4-5- toothed ; anthers tipped with a slender inflexed appendage ; ovary none ; 

 style radiate-penioillate at summit.— Herbs or suffrutescent plants ; the leaves alternate, coarsely toothed 

 or lobed, or even bipinnatifid. Natives of America, from the Saskatchewan to Peru. 



