| Silver Bush Lupine |
| Lupinus albifrons var. albifrons |
| Family: Fabaceae (Legume) |
Flowers:
| color | violet |
| style | pea |
Silver Bush Lupine has a classic pea flower [see Pacific pea]. The upper banner is lavender on top but each half curls backwards, revealing darker violet. The lower wings are blue to lavender to white with some white stripes, they curl and hide the keel that holds all the goodies. Dune bush lupine has similar but more purple flowers.
Flowers grow in whorls around the extending stem. A stem may grow 12 inches long and hold several dozen flower buds. Pollinated flowers develop into classic peapods, roughly 1.5 inches long. These pods develop under tension and have quite a bit of torque. When the seeds are mature, the pod springs open. Each straight half of the pod curls quickly, casting the seeds several feet away from the plant.
Observed blooming in February on a hillside; a specimen near the golf course was blooming in November [before the rains]. The flowers have heavenly aroma!
Habit:
Perennial shrub with mounding appearance. Columnar, taller than wide, in youth, spreading, wider than tall in maturity, up to eight feet tall. Every rainy season a branch extends a new stem with fresh leaves that will produce flowers. The compound leaf is palmate, leaflets spreading radially from its petiole, short stem. Each green leaflet is oblanceolate, lance-shaped, but wider near the tip. Some leaves appear paler, as if dusted with talcum powder.
I once noticed a great deal of Argentine ant activity on a Silver Bush Lupine just starting to bloom, especially on the budding stem ends. These ants normally remain on landscaped properties with irrigation and don't venture into the dry chaparral. This caused me to wonder if the ants were after nectar and involved in pollination. Then I spied something bright green on one of the buds: many large aphids, presumably satiated. I recognized another case of symbiosis. The ants were transporting aphids to this lupine bush, the aphids were extracting sap from the bush, then the ants would 'milk' the aphids to collect their 'nectar' and feed the ant colony. The ants must have maintained the aphids during the long dry season. Alas, the lupine was a loser in this transaction, but it got washed clean in the next rain.
When I harvested some seeds from a specimen on the golf course, I found small worms in the place of some seeds. It is possible that a moth pollinates these lupines and lays eggs in the flower, a symbiosis [inter-species cooperation] used by some yuccas.
This species of bush lupine has at least four distinct forms; this subspecies has paler blooms than its relatives. The darker-leaved Dune Bush Lupine grows in BMER on the west side of Hwy 1. The [darker] Santa Barbara and [paler] Lompoc ceanothus share the same territorial split.
Open sun in the coastal scrub, grassy areas.