358 UMBELUFERAE (PARSNIP FAMILY) 



rise to a tuft of leaves and longer peduncles (occasionally bearing a small 

 leaf): leaves with the ultimate divisions linear: peduncles reaching a height 

 of 3-3 dm.; umbel of vinequal rays, no involucre, dnd involucels of sinall linear 

 bractlets; rays 1-3.5 cm. long; pedicels 2-4 mm. long; flowers yellow: fruit 

 oblong, 6-7 mm. long, the dorsal and intermediate wings sometimes reduced 

 in breadth; oil-tubes 3-5 in the intervals, 6 or more on the commissural side: 

 seed face with broad and shallow concavity, 'but in immature specimens 

 sometimes appearing plane. — Interior Wyoming to Nevada and Orefgon: 



2. Pteryxia albiflora Nutt. T. & G. Fl. 1: 625. 1840.' Xow, very leaf y at 

 base: leaves pale, the ultimate segments divaricate and oftein 3-cleft, shortj, 

 aoiite: peduncles slender, more or less sjireading,' 1-1.6 dm. high,' consid- 

 erably longer than the leaves; umbels with uneqlial rays, no involucre, and 

 involucels of several linear bractlets; rays 4-12 mm. long; fruiting pedifels 

 3 mm. long; flowers white: fruit nearly orbicular; 4 mm. long, each carpel 

 with usually 5 more or less undulate wings.— Northern Wyoihing,' Idaho, and 

 Montana. 



20. THASPIUM Nutt. 



Perennials, with temately compound leaves and broad serrate or toothed 

 leaflets (or lower leaves simple), mostly no involucre, involucels; of small 

 bractlets, mostly yellow flowers, and all the fruits pediceled. Calyx-teeth 

 conspicuous. Fruit ovoid to oblong, mostly glabrous. Carpel with 3 or 4 

 or all the ribs strongly winged; stylopodium wanting; style long;, oil-tubes 

 solitary in the intervals, 2 on the commissural side. Seed face plane. / ^ i 



1. Thaspium trifoUatum aureum (Nutt.) Brit. Mem. Toir. Club 5: 240, 

 1894. Glabrous, 6-15 dm. high: basal leaves mostly cordate, serrate; stem 

 leaves simply temate (rarely bitemate); leaflets pvate to lanceolate, rounded 

 or, tapering at base, serrate: umbels 8-12-rayed; rays 1-2.5 cnj. Iqng; pedicels 

 about 2 mm. long; flowers yellow: fruit globose-ovoid, about 4 mm, long, all 

 the ribs equally winged, t. trifoliatum in part. — "Wyoming and eastwani. 



21. AULOSPERMUM C. & R. 



Caulescent or acaulescent plants, with more or less pinnately dissected 

 leaves (or primary division temate), mostly no involucre, involucels of small 

 narrow bractlets, which are not at all hyaline, and white, yellow, or piu^jlp 

 flowers. Calyx-teeth evident. Fruit oblong to orbicular in outhne, glabrous. 

 Carpel with 3-5 usually broad wings which are sometimes thickened at; in- 

 sertion, and with narrow or broad intervals; stylopodium wanting; oil-tubes 

 several in the intervals, 2 or more on the commissural' side. ' Seed not dor- 

 sally flattened or but slightly so, the face usually "with a narrow and deep 

 sulcus. — Cymopterus in part. 



Stems becoming caulescent, crowned with a duster of leaves and pe- 

 duncles. . 

 Flowers yellow. 

 Leaves coarsely dissected . • • • . , ••!. A. long^MS. 

 Leaves more finely dissected • • • • a • ^2. A. angustum. 

 Flowers white or purplish. 

 Flowers white . . , . . . . . . . 3. A. ibapense. 



Flowers purple . .4. A, planosum. 



Stems acaulescent 6. A. purpureum, 



1. Aulospennum longipes (Wats.) C. & R. Contrib. Nat. Herb. 7:, 175. 

 1900. Glabrous and glaucous: leaves pinnate to bipinnate, the ultimate seg- 

 ments oval and mucronulate: fruiting peduncles longer than the leives, 

 10-25 cm. long; umbels 5-10-rayed, with no involucre, krid involucels of sub- 

 ulate acuminate bractlets; rays 12-40 mm. long; pedicels 4-6 mm. long; 

 flowers yellow; fruit 6-8 mm, long, the 5 carpel wings broad and thin, some- 

 what unequal; oil-tubes 3-4 in the intervals, 6 on the commissural side: seed 

 face with deep and narrow sulcus, which broadens into a central, payity.r- 

 Naked clay soils in the desert areas; Colorado, Utah, and 'Wyoniin^'. ' 



