186 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
Low dry ground glabrous plants, with leaves and peduncles in a 
cluster at the summit of a short slender stem (more or less subterra- 
nean) arising from a very thick elongated root, once or twice pinnate 
thick or coriaceous leaves with broad segments, no involucre, involu- 
cels of rather conspicuous bractlets,and white flowers. Name from 
pvoos, wrinkled, and mrEpor, wing. 
Type species, Rhysopterus plurijugus C. & R. 
A genus of 3 species, belonging to the arid regions of Utah, Nevada, 
and eastern Oregon. 
The genus resembles Cymopterus, and especially CL newberryi in habit, but has a 
very different fruit, which most closely resembles that of Oreowis, but the latter has 
sharper ribs, flat-faced carpels, and very different foliage and habitat. 
Primary leaf divisions 8, terminal largest, laterals deeply 2-lobed, 
Umbels several, forming a compact cluster. ......2---..-------- 1. R. plurijugus, 
Umbels usually solitary ...........2.-----.222--------------------- 2. BR. jonesii. 
Primary leaf divisions 5, basal pair largest and pinnately3 to 5-cleft.. 3. RR. corrugatus. 
1. Rhysopterus plurijugus ©. & h.. sp. nov. Kia. 55. 
Leaves coriaceous, 2 to 3 em. long, on very short petioles, with 
broadly oblong or ovate and obtuse outline; leaflets 3, the laterals 
deeply 2-lobed, the terminal one much 
larger and usually 3-lobed, all the lobes 
somewhat cleft) and coarsely crenate- 
mucronate-toothed; peduncles — shorter 
than the leaves; umbels several, forming 
a compact cluster, with involucels of ovate 
Fig. 55,—Rhysopterus plurijugus: acuminate bractlets distinct nearly to the 
AOD KS. base: rays very stout, 8 to LO mm. long; 
fruiting pedicels 1 to 3 mm, long, shorter than those of the sterile 
flowers; fruit 3 mm. long, an accessory pair of corky ribs on the commis- 
sural side of the laterals, giving the appearance of a T-ribbed earpel. 
Type locality, Malheur Valley, near Harper ranch, Oregon, altitude 
1,000 meters; collected by Leberg, no. 2240, June LO, 1896; type in 
U.S. Nat. Herb. 
Only known from the type locality. 
Spectmens examined: 
OREGON: Type specimen as cited under type locality, 
2. Rhysopterus jonesii C. & R., sp. nov. 
Resembling 2. plurdjugus, but leaves somewhat fleshy, with longer 
petioles, and the teeth not mucronate; umbels solitary and on longer 
peduncles. 
Type locality, Juab, Utah, altitude 1,200 meters; collected by Jones, 
no. 1691, April 30, 1880; type in U. S. Nat. Herb. 
Only known from the type locality. 
Specimens examined: 
Uran: Type specimen as cited under type locality. 
Se 
sp J 
