Eriogonum umbellatum Torrey.
Sulfur flower
Family: Polygonaceae
Habit: Shrub, 10 to 200 cm. with densely tomentose leaves (esp. below); flowers yellow becoming reddish.
Distribution: Abundant in dry, open, often rocky places; California to western Canada, Colorado and New Mexico. An extremely variable plant.
Seed unit: Three-sided achene.
Seed: 2 to 5 mm. long, glabrous, lance ovoid, outer wall (pericarp) firm, brittle.
Embryo: Peripheral, curved embryo with hard, starchy endosperm.
Purity instructions: Pure seed definition:
AOSA: PSU #29 – Intact achene with or without perianth, whether or not a seed is present. Pieces of broken achene larger than one-half of the original size, unless no seed is present.
Lab notes: Often achenes with floral parts are immature and empty.
Average pure seed units per gram: 407 seeds per gram (based on AOSA pure seed units only from 23 samples received for testing from 1992 to 2001.
Range of percent pure seed: 50% to 95%
Range of percent inert: 4% to 49%
Description of inert: Broken seed, plant material, live insects.
Planting instructions: 400 seeds, TB, 21 days @ 20°C; for fresh and dormant seed, prechill recommended.
References: (link to main reference page)
Hickman, J.C., Ed. 1993. p. 880.
Munz, P.A. and D.D. Keck. 1968. p. 336.
Ransom Seed Laboratory
