Isocoma menziesii  (Hook & Arn.) G. Nesom
Coastal Goldenbush (syn. Haplopappus venetus (Kunth) S.F. Blake)

Family:  Asteraceae

Habit:  Subshrub, mat forming to 2 meters, yellow flowers.

Distribution:  Found in coastal and inland sandy soils in central and south coastal California, the Channel Islands and Baja California.  Isocoma menziesii is highly variable and complex with three varities: menziesii, sedoides, and vernonioides.

Seed unit:  Achene.

Seed:  Silky-hairy, tan-white, 3.5 mm. long with pappus 3 to 5 mm. long.

Embryo:  Well-developed cotyledons with no endosperm.

Purity instructions:  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 size.
ISTA: PSD#1 – Achene with or without pappus, unless it is obvious that no seed is present.

Lab notes:  There are often many immature, shriveled fruits.

Average pure seed units per gram:  2,081 seeds per gram (based on AOSA pure seed units only from 46 samples received for testing from 1993 to 2002).  

Range of percent pure seed:  8% to 56%

Range of percent inert:  43% to 90%

Description of inert:  Broken seed, sticks, plant material, 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. 295.
Ransom Seed Laboratory    
Smith, C.F.  1998.  p. 170.