Torrey and A. Gray
Shrub 3 to 9 dm. high; branched, tomentose, with glabrate
Dry scrub and Joshua tree woodland of the Great Basin and the
Mojave Desert in California, Oregon, Idaho and Utah.
3 to 5 mm., with short, stiff hairs; ribs glandular;
pappus of many fine bristles
6 to 8 mm.
Foliar with well-developed cotyledons, no endosperm.
Pure seed definition:
AOSA: PSU# 50 - Intact achene, with or without one or more of
the following structures: beak, bristle, hairs, pappus, wing, or
firmly attached floral remnants, provided a true seed with some
degree of embryo development can be detected (either by slight
pressure or by examination over light).
Piece of broken achene larger than one-half of the original
size, unless no seed is present. Seed, with or without
pericarp/seed coat; if broken, larger than one-half the original
ISTA: PSD #4 – Achene, with or without pappus, unless it is
obvious that no seed is present.
seed units per gram:
529 seeds per gram (based on AOSA pure seed units only from 1
sample received for testing in 2002).
percent pure seed:
Broken seed, plant material.
seeds, TB, 21 days @ 20°C; for fresh and dormant seed, prechill recommended.
to main reference page)
Hickman, J.C., Ed. 1993. p. 352.
Munz, P.A. and D.D. Keck. 1968. p. 1256.
Ransom Seed Laboratory