642 UMBELLIFERjE. Musenium. 



pressed, but not contracted at the commissure. Intervals broad and a little 

 convex, dark green. Seed free, but without any cavity between it and the 

 pericarp, 



47. MUSENIUM. Nutt. mss. 



" Margin of the calyx 5-toothed ; the teeth persistent. Petals obovate ; the 

 point inflexed. Styles slender, reflexed, rather long. Fruit ovate or ovate- 

 oblong, laterally compressed. Carpels more or less minutely scabrous, with 

 6 filiform acute slightly prominent ribs. Intervals with 2-3 vittae. Com- 

 missure with 4 vittfe. Carpophore 2-cleft. Seed with the sides moderately 

 incurved. Perennial dwarf rather foetid resiniferous (North American) herbs, 

 with fusiform roots, and a short caudex, or branching dichotomously from the 

 base. Leaves 2-3-pinnatifid. Involucre none. Involucels unilateral, of a 

 few rather rigid narrow leaflets. Flowers yellow or white." Nutt. 



§ 1 . Stem dichotomous : floivers yellow. 



1. M. divaricatum (Nutt. ! mss.) : decumbent ; stem short, dichotomously 

 branching from the base ; leaves bipinnatifid ; divisions confluent with the 

 winged rachis ; segments short, rather acutely toothed ; fruit somewhat gla- 

 brous. — Seseli divaricatum, Pursh, ft. 2. p. 1Z2? ; Nutt. gen. 1. p. 194 ; 

 DC. prodr. 4. p. 146. 



/?. Hookeri : rachis narrow ; fruit scabrous, with elevated points. — M. 

 Hookeri, Nutt.! mss. Seseli divaricatum. Hook. ! fl. Bor.-Am. 1. p. 264;. 

 Sims, hot. 7nag. t. 1742. (ex Hook.) 



Naked and arid hills and plains of the Upper Missouri, Nuttall ! ft. Plains 

 of the Upper Platte, near the Rocky Mountains, Nuttall! On the Saskatch- 

 awaii, Drummond! Douglas. May. — Plant about a span long. Leaves all, 

 except the radical ones, opposite, glabrous and shining : petiole and rachis 

 distinctly winged : lamina with an ovate outline ; primary and secondary 

 divisions 3-4 pairs ; the segments about one-third of an inch long, 3-4- 

 toothed. Peduncles 4-5 inches long, scabrous, naked, rigid, stout. Umbels 

 10-20-rayed ; the rays (in fruit) about half an inch long. Fruit 2 lines long, 

 oblong-ovate : pericarp thin : vittce filled with a strong terebinthine oil. — 

 The plant exudes small drops of resin spontaneously. 



2. M. trachyspermum (Nutt. mss.) : "decumbent; leaves bipinnatifid; 

 segments pinnatifid, rather obtuse, the lobes often 2-3-cleft and very short ; 

 rachis ^vide ; fruit short, oval, pulverulently scabrous." 



" With the preceding, to which it is nearly allied, but diff'ers in the fruit; 

 which is only half as large, the breadth nearly equalling the length. Invo- 

 lucel about 8-leaved, short." Nuttall. 



3. M. angustifolium (Nutt. ! mss.) ; " decumbent, with several stems from 

 one root ; leaves bipinnatifid, with a wide rachis ; the uppermost almost sim- 

 ply pinnatifid ; segments lanceolate, entire, or acutely denticulate ; fruit ellip- 

 tical, slightly scabrous. 



" Plains of the Upper Platte, witliin the Rocky Mountains. — Differs from 

 the preceding species in the longer leaves, and distant, narrow, less divided 

 segments." Nuttall. 



§ 2. Stemless : flowers ivhite. — Daucophyllum, Nutt. mss. 



4. M. tenuifolium (Nutt. ! mss.) : erect and somewhat cffispitose ; leaves 



