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Gleditsia triacanthos

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: GleditsiaView Description 

Habit: Tree, generally armed (generally unarmed in cultivation); +- dioecious. Leaf: of new stems alternate, irregularly odd-2-pinnate, of old stems on spurs, odd-1-pinnate. Inflorescence: on spurs, +- catkin-like, pendent. Staminate Inflorescence: flowers clustered, pedicels 0 to short. Pistillate Or Bisexual Inflorescence: flowers generally spaced, pedicels > short. Flower: radial, perianth hairy, sepals, petals each 3--5, +- alike except petals > sepals; stamens generally 5--7[8]. Fruit: +- indehiscent, oblong to ovate, compressed side-to-side yet plump, pulpy, dry, leathery in age. Seed: [1]many.
Species In Genus: 13--16 species: 2--3 in eastern North America, 1 in South America, 8--10 in eastern and southeastern Asia. Etymology: (J.G. Gleditsch, German botanist, 1714--1786)

Gleditsia triacanthos L.
Leaf: deciduous; 2-pinnate leaves with 1° leaflets 7--17, 2° leaflets 4--20, elliptic to oblong, 1.3--2.5 cm, glabrous; 1-pinnate leaves with leaflets 20--28, 1.5--3.5 cm. Staminate Inflorescence: 1--several per spur, 3.5--8 cm, simple or branched at tip. Pistillate Inflorescence: 1 per spur, 3--5 cm, simple. Flower: perianth yellow-green, +- 3 mm (staminate), 4--5 mm (pistillate flower); stamens 5--7. Fruit: 1--3 per peduncle, 20--40 cm, 2.5--3 cm wide, generally curved, often twisted, hairy in youth, brown, glabrous, shiny, persistent in age.
Ecology: Uncommon. Moist riparian to dry upland woodland; Elevation: < 800 m. Bioregional Distribution: ScV, PR, expected elsewhere; Distribution Outside California: central and eastern United States, widely cultivated. Flowering Time: May--Jun
eFlora Treatment Author: Martin F. Wojciechowski
Jepson Online Interchange
Weed listed by Cal-IPC

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Citation for this treatment: Martin F. Wojciechowski 2016. Gleditsia triacanthos, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on October 24, 2016.

Citation for the whole project: Jepson Flora Project (eds.) 2016. Jepson eFlora,, accessed on October 24, 2016.

Geographic subdivisions for Gleditsia triacanthos:
ScV, PR, expected elsewhere;
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.
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CCH collections by month

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