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	©Copyright 1993 by the Regents of the University of California Print edition is available from the University of California Press

	The second edition of The Jepson Manual (2012) is available from the University of California Press
	See also the Jepson eFlora, which parallels the Second Edition

CACTACEAE

CACTUS FAMILY

Edward F. Anderson (except Opuntia)

Perennial, shrub, tree, generally fleshy
Stem cylindric, spheric, or flat; surface smooth, tubercled, or ribbed (fluted); nodal areoles bear flowers, generally bear spines from center ("central spines") and margin ("radial spines") (Opuntia areoles bear small, barbed, deciduous bristles sometimes called glochids, generally also bear spines)
Leaf generally 0
Flower generally solitary, bisexual, sessile, ± radial; perianth parts generally many, grading from scale-like to petal-like; stamens many; ovary appearing inferior, ± submerged in stem, so generally with areoles on surface, style 1, stigma lobes generally many
Fruit generally fleshy, generally indehiscent, spiny, scaly, or smooth
Seeds many
Genera in family: 93 genera, ± 2000 species: especially Am deserts; many cultivated
Etymology: (Greek: thorny plant)
Reference: [Benson 1982 Cacti of US & Can; Hunt & Taylor eds 1990 Bradleya 8:85–107]

OPUNTIA

PRICKLY-PEAR, CHOLLA

Bruce D. Parfitt and Marc A. Baker

Shrubs, trees; roots fibrous
Stem generally erect, < 12 m; segments flat to cylindric, generally firmly attached; tubercles generally elongate along stem; ribs sometimes present; spines 0–many, sometimes flat, tip smooth or barbed, epidermis persistent or separating as a papery sheath; small, barbed deciduous bristles generally many
Leaf small, conic, fleshy, deciduous, obvious on young stems and ovaries
Fruit juicy, fleshy or dry; wall thick, bearing areoles
Seed dark brown, encased in a bony, whitish aril
Species in genus: 200 species: Am; O. ficus-indica cultivated for food, others for ornamental
Etymology: (Possibly from Papago Indian name ("opun") for this food plant; or named for a spiny plant of Opus, Greece)
Spines smaller, fewer in shade forms; when yellow, blacken with age. Hybridization common within subgenera.

Native

O. erinacea Engelm. & J.M. Bigelow

Stem clumped; branches generally ascending to erect, generally < 0.5 m tall; segments, 5.5–18 cm, flat, elliptic to obovate; spines 1–24, longest 1.7–13 cm, flat to round, straight to wavy, generally whitish, base yellow-brown, surrounded by shorter, generally reflexed, whiter spines
Flower: inner perianth 2–2.5 cm, yellow to pink-magenta; filaments generally white (magenta); style white, stigma green
Fruit 2.5–4 cm, generally spiny, green, tinted red, becoming dry, tan; areoles 14–68
Seed 5–6.5 mm
Ecology: Creosote-bush to pine scrub
Elevation: 900–3300 m.
Bioregional distribution: se High Sierra Nevada, San Bernardino Mountains, San Jacinto Mountains, East of Sierra Nevada, Mojave Desert (especially Desert Mountains)
Distribution outside California: to Washington, Rocky Mtns, New Mexico
Recent taxonomic note: Opuntia polyacantha Haw. var. erinacea (Engelm. & J.M. Bigelow) B.D. Parfitt

Native

var. utahensis (Engelm.) L.D. Benson

Stem: spines 1–7 per areole, generally in < 50% of areoles, longest 1.7–5.5 cm, spines on lower edge of areoles 0–4, straight, ± reflexed
Fruit: spines 0(–4); areoles 14–26
Chromosomes: 2n=88
Ecology: Sage scrub to Jeffrey-pine woodland
Elevation: 2000–2800 m.
Bioregional distribution: East of Sierra Nevada (Mono, nw Inyo cos.)
Distribution outside California: to Idaho, Utah, New Mexico
Flowering time: Jun–Jul
Synonyms: O. rhodantha K. Schum., O. xanthostemma K. Schum
Horticultural information: DRN, DRY, SUN: 1, 2, 3, 7, 10, 18
Recent taxonomic note: Opuntia polyacantha Haw. var. erinacea (Engelm. & J.M. Bigelow) B.D. Parfitt