Lasthenia californica

Lasthenia californica Lindley
Goldfields, California Lasthenia (syn. Lasthenia chrysostoma)

Family:  Asteraceae

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