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Acmispon americanus var. americanus

Higher Taxonomy
Family: Fabaceae (Leguminosae)View DescriptionDichotomous Key

Habit: Annual to tree. Leaf: generally alternate, generally compound, generally stipuled, generally entire, pinnately veined Inflorescence: generally raceme, spike, umbel or head; or flowers 1--few in axils. Flower: generally bisexual, generally bilateral; hypanthium 0 or flat to tubular; sepals generally 5, generally fused; petals generally 5, free, fused, or lower 2 +- united into keel (see 3, Key to Groups, for banner, wings); stamens 10 or many (or [1], 5, 6, 7, 9), free or fused or 10 with 9 filaments at least partly fused, 1 (uppermost) free; pistil 1, ovary superior, generally 1-chambered, ovules 1--many, style, stigma 1. Fruit: legume, including a stalk-like base (above receptacle) or not. Seed: 1--many, often +- reniform, generally hard, smooth.
Genera In Family: +- 730 genera, 19400 species: worldwide; with grasses, requisite in agriculture, most natural ecosystems. Many cultivated, most importantly Arachis, peanut; Glycine, soybean; Phaseolus, beans; Medicago, alfalfa; Trifolium, clovers; many orns. Note: Unless stated otherwise, fruit length including stalk-like base, number of 2° leaflets is per 1° leaflet. Upper suture of fruit adaxial, lower abaxial. Anthyllis vulneraria L. evidently a waif, a contaminant of legume seed from Europe. Laburnum anagyroides Medik., collected on Mount St. Helena in 1987, may be naturalized. Ceratonia siliqua L., carob tree (Group 2), differs from Gleditsia triacanthos L. in having evergreen (vs deciduous) leaves that are 1-pinnate (vs 1-pinnate on spurs on old stems, 2-pinnate on new stems) with 2--5(8) (vs 7--17) 1° leaflets, commonly cultivated, now naturalized in southern California. Aeschynomene rudis Benth. , Halimodendron halodendron (Pall.) Voss (possibly extirpated), Lens culinaris Medik. are agricultural weeds. Caragana arborescens Lam. only cult. Ononis alopecuroides L. , Sphaerophysa salsula (Pall.) DC. all evidently extirpated. Cercidium moved to Parkinsonia; Chamaecytisus to Cytisus; Psoralidium lanceolatum to Ladeania.
eFlora Treatment Author: Martin F. Wojciechowski, except as noted
Scientific Editor: Martin F. Wojciechowski, Thomas J. Rosatti.
Genus: AcmisponView DescriptionDichotomous Key

Habit: Annual, perennial herb, shrub, unarmed. Leaf: generally odd-1-pinnate (or +- palmately compound, rarely some or most simple); stipules often gland-like, bump-like, or conic, often not apparent; leaflets 3--9, generally irregularly arranged, lowest not stipular in position. Inflorescence: umbel or 1--2-flowered, axillary, generally peduncled, often bracted. Flower: corolla generally yellow (white, pink), fading darker; 9 filaments fused, 1 free. Fruit: dehiscent or not, exserted from calyx or not, ovoid to oblong, +- beaked. Seed: 1--several.
Species In Genus: +- 23 species: southwestern Canada, western United States, Mexico, 1 sp. in Chile. Etymology: (Greek acme, point, apex, probably for the hooked-tipped fruit) Note: Intermediates may be hybrids.
Unabridged Note: Pollen has 4(7) apertures.
eFlora Treatment Author: Luc Brouillet

Acmispon americanus (Nutt.) Rydb. var. americanus
Habit: Annual, generally hairy. Stem: prostrate to erect, simple or openly branched, 0.5--6 dm. Leaf: pinnate or +- simple; stipules gland-like; leaflets generally 3, generally 10--20 mm, lanceolate to elliptic; axis not flat. Inflorescence: 1-flowered, peduncle (3--10)15 mm, bracts simple. Flower: calyx 2.5--6.5 mm, lobes >> tube, hairs soft-shaggy; corolla 5--9 mm, +- white or yellow to pink, wings +- = keel, stigma glabrous. Fruit: dehiscent, spreading or pendent, +- entirely exserted, 1.5--3 cm, oblong, +- straight, generally flat, beak curved, 0.9--1.7 mm. Seed: 3--8. Chromosomes: 2n=14.
Ecology: Coast, chaparral, mountain forest, water courses, roadsides, other disturbed areas; Elevation: < 2400 m. Bioregional Distribution: CA (exc DSon); Distribution Outside California: to Canada, central United States, Mexico. Flowering Time: May--Oct Note: Many races, ecological forms.
Synonyms: Lotus purshianus Clem. & E.G. Clem. var. glaber (Nutt.) Munz; Lotus purshianus var. purshianus
eFlora Treatment Author: Luc Brouillet
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botanical illustration including Acmispon americanus var. americanus


Citation for this treatment: Luc Brouillet 2017. Acmispon americanus var. americanus, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on September 23, 2017.

Citation for the whole project: Jepson Flora Project (eds.) 2017. Jepson eFlora,, accessed on September 23, 2017.

Acmispon americanus var. americanus
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© 2014 Neal Kramer
Acmispon americanus var. americanus
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© 2015 Steve Matson
Acmispon americanus var. americanus
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© 2008 Keir Morse
Acmispon americanus var. americanus
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© 2014 Neal Kramer
Acmispon americanus var. americanus
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© 2005 Christopher L. Christie
Acmispon americanus var. americanus
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© 2015 Steve Matson

More photos of Acmispon americanus var. americanus in CalPhotos

Geographic subdivisions for Acmispon americanus var. americanus:
CA (exc DSon);
Markers link to CCH specimen records. Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues. Purple markers indicate specimens collected from a garden, greenhouse, or other non-wild location.
map of distribution 1
(Note: any qualifiers in the taxon distribution description, such as 'northern', 'southern', 'adjacent' etc., are not reflected in the map above, and in some cases indication of a taxon in a subdivision is based on a single collection or author-verified occurence).

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Data provided by the participants of the Consortium of California Herbaria.
View all CCH records

CCH collections by month

Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa.
Blue line denotes eFlora flowering time.