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Key to families | Table of families and genera
This text currently parallels The Jepson Manual: Vascular Plants of California, Second Edition that is now available at the University of California Press.
Text appearing in blue on this page will not appear in the printed book; it will be displayed only on the Web. Specimen numbers are hyperlinked to records in the Consortium of California Herbaria data view where possible. Taxa are hyperlinked to entries in the Jepson Interchange via the "[Online Interchange]" link.
Annual, perennial herb, glabrous or hairy; generally monoecious.
Stem: ascending to erect, generally < 1 m; branches equally forked.
Leaf: cauline, generally alternate, occasionally opposite; stipules 0 or gland-like; generally ± sessile; leaf base symmetrical.
Inflorescence: ± flower-like, generally clustered; clusters whorled in umbel-like, or cyme-like, bracted arrays; involucre generally < 5 mm, ± bell-shaped, bracts 5, fused, glands 4–5, alternating with bracts, appendages generally 0; flowers central.
Staminate flower: 5–many, in 5 clusters around pistillate flower; sepals 0; stamens 1.
Pistillate flower: 1, central, stalked; sepals 0; ovary chambers 3, styles 3, generally fused at base, divided or simple.
Fruit: capsule, round to 3-angled or -lobed in ×-section.
Seed: round or angled in ×-section; surface smooth or sculptured, generally with a knob-like structure at attachment scar.
± 1500 species: warm temperate to tropics, worldwide. (Euphorbus, physician to the King of Mauritania, 1st century) [Wheeler 1936 Bull S Calif Acad Sci 35:127–147] Forms monophyletic group with Chamaesyce, often included in Euphorbia. Euphorbia myrsinites L., Euphorbia rigida L. Bieb. occasionally in gardens but not considered naturalized; Euphorbia serrata L. <WEEDINESS SYMBOL 1> considered extirpated from CA; Euphorbia marginata Pursh occasionally persisting from gardens, but recent records lacking. Euphorbia graminea Jacq. <WEEDINESS SYMBOL 1> an urban weed.
1. Involucre with white petal-like appendages on glands
2. Lvs opposite, margin serrate; seed with a minute knob at tip ..... E. exstipulata var. exstipulata
2' Lvs alternate, margin entire; seed without a knob ..... E. misera
1' Involucre ± without obvious white petal-like appendages on glands
3. Infl clustered at branch tips; involucre glands 1–3(5), cupped
4. Involucre and fruit hairy; seed flattened, oblong ..... E. eriantha
4' Involucre and fruit generally glabrous; seed ellipsoid to ovoid
5. Bracts red at base, tip green; stem glabrous ..... [E. cyathophora]
5' Bracts uniformly green or ± white; stem hairy
6. Hairs on distal stems and abaxial leaf faces, recurved; seed width >= 2.2 mm, surface coarsely tubercled ..... [E. davidii]
6' Hairs on distal stems and abaxial leaf faces ± straight, spreading; seed width <= 2.1 mm, surface finely tubercled ..... [E. dentata]
3' Infl open, whorled at branch tips, alternate proximal to whorl; involucre glands 4(5), flat
7. Lvs opposite throughout, 4-ranked; fruit >= 8 mm ..... E. lathyris
7' Lvs alternate proximal to inflorescence; fruit <= 6 mm
8. Lf margin finely to coarsely toothed
9. Lf tip acute ..... E. terracina
9' Lf tip rounded, obtuse or notched
10. Perennial; stem densely hairy ..... E. oblongata
10' Annual; stem glabrous or sparsely hairy
11. Whorled cyme branches 5; staminate flowers 8–12; style divided < 1/2 ..... E. helioscopia
11' Whorled cyme branches 3; staminate flowers 5–10; style ± free, divided nearly to base ..... E. spathulata
8' Lf margin generally entire (finely crenate)
12. Shrub ..... E. dendroides
12' Annual to perennial herb
13. Lf linear, lanceolate to oblanceolate; seed surface smooth ..... E. virgata
13' Lf elliptic to (ob)ovate or spoon-shaped; seed surface generally pitted or low ridged, occasionally ± smooth
14. Seed 1–1.5 mm, surface with broad pits ..... E. peplus
14' Seed >= 2 mm, surface with low network of ridges to ± smooth; fruit lobes smooth
15. Annual (biennial); gland horns > gland width ..... E. crenulata
15' Perennial; gland horns < gland width
16. Lf sessile; stem ascending to erect; gland margin 2-horned, entire to scalloped between horns ..... E. lurida
16' Lf narrowed to short petiole; stem ascending to decumbent; gland margin truncate, scalloped ..... E. schizoloba
Citation for the whole project: Jepson Flora Project (eds.) [year] Jepson eFlora, http://ucjeps.berkeley.edu/IJM.html [accessed on month, day, year]
Citation for an individual treatment: [Author of taxon treatment] [year]. [Taxon name] in Jepson Flora Project (eds.) Jepson eFlora, [URL for treatment]. Accessed on [month, day, year].
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