Arnica arachnoidea

Arnica arachnoidea Rydberg, sp. nov
Rootstock horizontal; stem 2-4 dm. high; sulcate, long-villous with crisp hairs, almost arachnoid, especially at the bases of the k-aves; leaves of tinoffsets with petioles 2 S cm. long, the blades oval, obtusish, 5-7 cm. long, subarachnoid villous on both sides; stem-haves 3 or 4 pairs, tinlower ones short-petioled, their blades oval, 1 10 cm. long, 2-4 cm. wide, acute 01 obtuse at the apex, tapering at tinbase, entire or rarely slightly denticulate, the upper li
sessile, lanceolate or lance-oblong; beads i 4; peduncles S 10 cm. long, sparingly villous and
glandular-puberulcnt ; involucre hemispheric, 12 mm. high, 15—20 mm. broad, villous ami
glandular, bracts 1 5 18, linear-lanceolate, acttminate; raj flowers 10 15, the ligules 10 14mm. long, 4-5 mm. wide, disk-corollas 7 mm. long; acneni hirsute, i mm long; pappus-bristles
light-brown, 6 7 mm. long, ihorl plumose.
Type eoUected hi Big I ottoowood < anon, bekra Silver l..ik<-. Utah, July 4, 1915, Ryil
r 6609 ii. r .1 ' -ild i
trio Mo-. Wasatch Mountains, ' tah.