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coastal bush lupine, tree lupine, yellow bush lupine

bicolor lupine, field lupine, Lindley's annual lupine, Lindley's lupine, lupine, miniature lupine, Montana lupine, small-flower lupine, two-color lupine, two-colour lupine

Habit Shrubs, usually 5–20 dm, green-glabrous or silver-hairy. Herbs, annual, 0.5–4 dm, pubescent.
Stems

ascending or erect, branched, woody.

ascending or erect, branched or unbranched.

Leaves

cauline;

stipules 8–12 mm;

petiole 2–3(–6) cm;

leaflets 5–12, blades 20–60 × 3–10 mm, adaxial surface glabrous.

cauline;

petiole 1–7 cm;

leaflets 5–8, blades 10–40 × 1–5 mm, adaxial surface glabrous or sparsely pubescent.

Racemes

10–30 cm;

flowers whorled or not.

4–20 cm;

flowers usually in fewer than 5 whorls, sometimes spirally arranged.

Peduncles

4–10 cm;

bracts deciduous, 8–10 mm.

3–10 cm;

bracts deciduous, 4–6 mm.

Pedicels

4–10 mm.

1–3.5 mm.

Flowers

14–18 mm;

calyx bulge or spur 0–1 mm, abaxial lobe entire, 5–7 mm, adaxial lobe 2-toothed, 5–9 mm;

corolla usually yellow, rarely lilac to purple, banner patch darker or not or white, banner glabrous abaxially, lower keel margins glabrous, adaxial margin ciliate from claw to tip.

4–10 mm;

calyx abaxial lobe entire, 4–6 mm, adaxial lobe deeply cleft, 2–4 mm;

corolla usually blue, rarely light blue, pink, or white, banner spot white, becoming magenta, upper keel margins usually ciliate near apex, rarely glabrous, sometimes blunt, banner longer than wide.

Legumes

4–7 cm, hairy.

1–3 × 0.3–0.6 cm, pubescent.

Cotyledons

deciduous, petiolate.

deciduous, petiolate.

Seeds

8–12, black to tan, often striped lighter, 4–5 mm.

5–8.

2n

= 48.

= 48.

Lupinus arboreus

Lupinus bicolor

Phenology Flowering Apr–Jul. Flowering late winter–spring (Mar–Jun).
Habitat Coastal bluffs, dunes, disturbed sand. Open or disturbed areas.
Elevation 0–100 m. (0–300 ft.) 0–1600 m. (0–5200 ft.)
Distribution
from FNA
CA; OR; WA; BC; Mexico (Baja California) [Introduced in South America (Argentina, Chile), Europe, Pacific Islands (New Zealand), Australia (including Tasmania)]
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; CA; OR; WA; BC; Mexico (Baja California, Baja California Sur, Sonora)
[WildflowerSearch map]
[BONAP county map]
Discussion

Lupinus arboreus is known from the central California coast southward to northern Baja California; it was introduced as a sand binder and has become naturalized in northern California, Oregon, Washington, and southern British Columbia.

Lupinus arboreus grades into L. rivularis in the North Coast of California. Plants with yellow petals and sweet-smelling flowers are widely cultivated as a sand binder. Hairier plants from the western San Francisco Bay area with yellow banners and blue wings have been called var. eximius; plants with glabrous leaflets and purple petals have been called L. propinquus. Lupinus arboreus hybridizes with L. littoralis and probably other species. Seeds of L. arboreus species are toxic.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Lupinus bicolor is naturalized in Arizona. The named subspecies and varieties do not conform to consistently recognizable geographical or morphological entities (D. B. Dunn 1955). Vigorous plants with larger flowers may be confused with L. nanus. In California, plants on the Outer North Coast Ranges may persist for two growing seasons. Lupinus bicolor (as L. polycarpus) has been reported from Alabama (A. R. Diamond 2016) and Michigan (E. G. Voss and A. A. Reznicek 2012).

Lupinus micranthus Douglas (1829, not Gussone 1828) is an illegitimate name that pertains here.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 11. FNA vol. 11.
Parent taxa Fabaceae > subfam. Faboideae > Lupinus Fabaceae > subfam. Faboideae > Lupinus
Sibling taxa
L. adsurgens, L. affinis, L. albicaulis, L. albifrons, L. andersonii, L. angustiflorus, L. antoninus, L. apertus, L. arbustus, L. arcticus, L. argenteus, L. arizonicus, L. benthamii, L. bicolor, L. brevicaulis, L. breweri, L. cervinus, L. chamissonis, L. citrinus, L. concinnus, L. constancei, L. covillei, L. croceus, L. dalesiae, L. diffusus, L. duranii, L. elatus, L. elmeri, L. excubitus, L. flavoculatus, L. formosus, L. fulcratus, L. gracilentus, L. grayi, L. guadalupensis, L. havardii, L. hirsutissimus, L. huachucanus, L. hyacinthinus, L. kingii, L. kuschei, L. lapidicola, L. latifolius, L. lepidus, L. leucophyllus, L. littoralis, L. longifolius, L. ludovicianus, L. luteolus, L. magnificus, L. malacophyllus, L. microcarpus, L. nanus, L. neomexicanus, L. nevadensis, L. nipomensis, L. nootkatensis, L. obtusilobus, L. odoratus, L. onustus, L. oreganus, L. pachylobus, L. padrecrowleyi, L. peirsonii, L. perennis, L. polyphyllus, L. pratensis, L. pusillus, L. rivularis, L. sabineanus, L. sericatus, L. sericeus, L. shockleyi, L. sierrae-blancae, L. sparsiflorus, L. spectabilis, L. stiversii, L. subcarnosus, L. succulentus, L. sulphureus, L. texensis, L. tidestromii, L. tracyi, L. truncatus, L. uncialis, L. villosus, L. westianus
L. adsurgens, L. affinis, L. albicaulis, L. albifrons, L. andersonii, L. angustiflorus, L. antoninus, L. apertus, L. arboreus, L. arbustus, L. arcticus, L. argenteus, L. arizonicus, L. benthamii, L. brevicaulis, L. breweri, L. cervinus, L. chamissonis, L. citrinus, L. concinnus, L. constancei, L. covillei, L. croceus, L. dalesiae, L. diffusus, L. duranii, L. elatus, L. elmeri, L. excubitus, L. flavoculatus, L. formosus, L. fulcratus, L. gracilentus, L. grayi, L. guadalupensis, L. havardii, L. hirsutissimus, L. huachucanus, L. hyacinthinus, L. kingii, L. kuschei, L. lapidicola, L. latifolius, L. lepidus, L. leucophyllus, L. littoralis, L. longifolius, L. ludovicianus, L. luteolus, L. magnificus, L. malacophyllus, L. microcarpus, L. nanus, L. neomexicanus, L. nevadensis, L. nipomensis, L. nootkatensis, L. obtusilobus, L. odoratus, L. onustus, L. oreganus, L. pachylobus, L. padrecrowleyi, L. peirsonii, L. perennis, L. polyphyllus, L. pratensis, L. pusillus, L. rivularis, L. sabineanus, L. sericatus, L. sericeus, L. shockleyi, L. sierrae-blancae, L. sparsiflorus, L. spectabilis, L. stiversii, L. subcarnosus, L. succulentus, L. sulphureus, L. texensis, L. tidestromii, L. tracyi, L. truncatus, L. uncialis, L. villosus, L. westianus
Synonyms L. arboreus var. eximius, L. propinquus L. bicolor subsp. marginatus, L. bicolor var. micranthus, L. bicolor subsp. microphyllus, L. bicolor var. microphyllus, L. bicolor subsp. pipersmithii, L. bicolor var. pipersmithii, L. bicolor var. rostratus, L. bicolor subsp. tridentatus, L. bicolor var. tridentatus, L. bicolor var. trifidus, L. bicolor subsp. umbellatus, L. bicolor var. umbellatus, L. congdonii, L. polycarpus
Name authority Sims: Bot. Mag. 18: plate 682. (1803) Lindley: Bot. Reg. 13: plate 1109. (1827)
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