Castilleja exserta

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