RANUNCULACEAE (BUTTERCUP FAMILY) 193 



least above; stem slender, simple, 1-3 dm. high, from a cluster of tuberous, 

 easily detachable roots: leaves firm, divided into linear segments: flowers 

 blue, slightly villous, slender-pediceled : sepals oblong, shorter than the 

 slender spur: lower petal 2-cleft, pubescent and with a tuft of hairs about the 

 middle: follicles pubescent or glabrate: seeds wing-angled above. (D. dume- 

 torum Greene, PI. Baker. 3: 4. 1901.) Western Nebraska through Wyoming 

 and Colorado to Utah. 



3. Delphinium tricolor Nutt. Journ. Acad. Phila. 7: 10. 1834. Glabrous 

 or pubescent, 2-3 dm. high, rather stout, from thickish fascicled deep-set 

 roots: leaves deeply parted, the segments cleft or parted into linear lobes: 

 raceme open, few-flowered, the lower pedicels elongated: flowers about 2 cm. 

 long: upper petals yellowish and copiously blue-veined: mature follicles 

 glabrous, erect or recurving. Northern Wyoming, west to Oregon. 



4. Delphinium scaposum Greene, Bot. Gaz. 6: 156. 1880. Glabrous; stems 

 scapose, 2-4 dm. high, from thickish branching roots: leaves clustered at the 

 base, short-petioled, round or reniform in outline, and mostly oblong or sub- 

 cuneate divisions and lobes: raceme several-flowered; the flowers blue: sepals 

 oblong, 10-14 mm. long, shorter than the somewhat curved spur: follicles 

 oval, erect: seeds with rugose and ariliform coat. Western Colorado to Ne- 

 vada. 



5. Delphinium Geyeri Greene, Erythea 2: 189. 1894. Canescently tomentu- 

 lose throughout; stems usually several or many from a bundle of woody deep- 

 set roots, 2-5 dm. high: basal leaves numerous and tufted, petioled; the cau- 

 line diminishing upward; all rather thick, cut into many linear segments, 

 these tipped with a white callosity: raceme long, with many azure-blue 

 flowers: spur horizontal or ascending, stoutish. This is the species that is 

 commonly known as POISON WEED. The tuft of radical leaves develops early 

 and these if eaten freely produce fatal bloating in cattle unless the animal 

 is relieved promptly by the use of a trochar. Very abundant on the plains 

 in our range. 



6. Delphinium carolinianum Walt. Fl. Car. 155. 1788. Puberulent or 

 pubescent; stem solitary, strict, simple or nearly so, 2-5 dm. high: leaves 

 3-5-parted or cleft, usually into linear lobes : raceme spicif orm, many-flowered : 

 flowers varying from blue to white or even greenish- white : sepals sometimes 

 tipped with brown: spur horizontal or ascending; petals rather heavily pilose: 

 follicles oblong, erect. D. azureum. (D. albescens Rydb. in Brit. Man. 

 417. 1901.) From the eastern base of the Rocky Mountains far to the 

 eastward. 



6a. Delphinium carolinianum Penhardii (Huth.) A. Nels. A form with 

 flowers mostly white and the spurs curved and erect. (D. Penhardii Huth. 

 Helios 10: 27. 1893; D. camporum Greene, Erythea 2: 183. 1894.) On the 

 great plains, eastward of the Rocky Mountains. 



7.. Delphinium sapellonis Ckll. Bot. Gaz. 34: 453. 1902. Very glandular 

 or viscid-pubescent, especially above; stem strict 8-18 dm. high: leaves 

 tripartite; the lateral divisions large and themselves almost tripartite; the 

 segments mostly linear: racemes long, narrow, many-flowered; flowers rather 

 small, dull-colored, greenish-brown and more or less streaked with dull purple: 

 spur ascending; petals somewhat pilose with yellow hairs. New Mexico, and 

 may reach Colorado. 



8. Delphinium scopulorum Gray, PL Wright. 2: 9. 1853. Glabrous below, 

 minutely pubescent in the inflorescence; stem usually simple, 3-8 dm. high: 

 leaves laciniately multifid ; the primary and secondary divisions cuneiform in 

 outline, laciniately many-cleft into lance-linear very acute segments: flowers 

 rather large, indigo-blue, in a strict raceme: spur longer than the sepals: 

 follicles erect, nearly glabrous. New Mexico and probably in southern 

 Colorado. 



9. Delphinium robustum Rydb. Bull. Torr. Bot. Club 28: 276. 1901. 

 Puberulent throughout; stem stout, often 2 m. or more high: leaves divided 

 into 5-7 segments which are 6-12 cm. long and twice cleft into linear lobes: 

 inflorescence branched, many-flowered: sepals elliptical, dark blue, as long as 



ROCKY MT. BOT. 13 



