Lasthenia californica Lindley
Goldfields, California Lasthenia (syn. Lasthenia chrysostoma)
Habit: Simple or freely-branched annual, less than 40 cm. tall, sometimes hairy.
Distribution: Abundant in many habitats in California, Arizona, Oregon and Mexico.
Seed unit: Achene.
Seed: Achene less than 3 mm., linear to club-shaped, grabrous or hairy. Pappus of 0 to 7 narrow awns or wider-awned scales.
Embryo: Foliar embryo.
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 #4 – Achene, with or without pappus, unless it is obvious that no seed is present.
Lab notes: Obviously empty, thin and transparent achenes are considered inert material. Use of a diaphanoscope is helpful.
Average pure seed units per gram: 8,669 seeds per gram (based on AOSA pure seed units only from 57 samples received for testing from 1994 to 2004).
Range of percent pure seed: 26 to 76%
Range of percent inert: 23 to 73%
Description of inert: Plant material, dirt, dead insects.
Planting instructions: 400 seeds, TB, 14 days @ 20°C; for fresh and dormant seed, prechill recommended.
References: (link to main reference page)
Hickman, J.C., Ed. 1993. p. 299.
Ransom Seed Laboratory