Castilleja exserta (A. A. Heller) Chuang and Heckard
Purple Owl’s-clover (syn. Orthocarpus purpurascens)
Family: Scrophulariaceae
Habit: Annual 10 to 45 cm., stiff hairy with purple flowers.
Distribution: Open fields, grasslands and woodlands of the Northwest, Sierra Nevada Foothills, coastal areas and inland through mountains of southern California, the Channel Islands, Arizona, and New Mexico.
Seed unit: Free seed.
Seed: 1 to 2 mm. free seed often has a loose, membranous, net-like outer seed coat, inner seed coat surface with cellular reticulation.
Embryo: Embryo is linear to spatulate in fleshy endosperm.
Purity instructions: Pure seed definition:
AOSA: PSU #1 – Seed, with or without seed coat/netted covering; broken seed larger than one-half the original size.
Lab notes: If ovoid capsule is found, seeds must be removed. Empty seed coat “nets” are considered inert.
Average pure seed units per gram: 13,744 seeds per gram (based on AOSA pure seed units only from 50 samples received for testing from 1995 to 2002).
Range of percent pure seed: 17% to 93%
Range of percent inert: 6% to 82%
Description of inert: Plant material, dead insects.
Planting instructions: 400 seeds, TB, 21 days @ 20°C; for fresh and dormant seed, prechill and GA3 recommended.
References: (link to main reference page)
Hickman, J.C., Ed. 1993. p. 1020
Ransom Seed Laboratory
