Jepson Flora Project: Jepson Interchange    

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Jepson Interchange (more information)
©Copyright 1993 by the Regents of the University of California
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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]



Stems 1–many, 2–30 cm, 2–20 cm diam, spheric to cylindric; ribs inconspicuous; tubercles round in X -section; central spines generally hooked
Flower 1–5 cm diam; ovary glabrous
Fruit ovoid to cylindric, red, glabrous
Seed black, pitted
Species in genus: 150 species: North America
Etymology: (Latin: nipple)
Reference: [Hunt 1984–87 Bradleya 2:65–96; 3:53–66; 5:17–48]


M. tetrancistra Engelm.

Stem generally 1, 7–25 cm, 3.5–7.5 cm diam, cylindric; axillary bristles 0; central spines 3–4, 18–25 mm, generally hooked, tips dark; radial spines 30–60 in 2–3 ranks, 10–25 mm, white or tips dark
Flower 30–40 mm, 25–40 mm diam; perianth deep pink to lavender
Fruit 15–32 mm, cylindric
Seed: aril corky
Chromosomes: 2n=22
Ecology: Uncommon. Sandy hills, valleys, plains, creosote-bush scrub
Elevation: 130–1400 m.
Bioregional distribution: Desert
Distribution outside California: to Utah, Arizona, n Mexico
Flowering time: Apr
Horticultural information: DRN, DRY; DFCLT.

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bioregional map for MAMMILLARIA%20tetrancistra being generated
YOU CAN HELP US make sure that our distributional information is correct and current. If you know that a plant occurs in a wild, reproducing state in a Jepson bioregion NOT highlighted on the map, please contact us with that information. Please realize that we cannot incorporate range extensions without access to a voucher specimen, which should (ultimately) be deposited in an herbarium. You can send the pressed, dried collection (with complete locality information indicated) to us (e-mail us for details) or refer us to an accessioned herbarium specimen. Non-occurrence of a plant in an indicated area is difficult to document, but we will especially value your input on those types of possible errors (see automatic conversion of distribution data to maps).

Retrieve Jepson Interchange Index to Plant Names entry for Mammillaria tetrancistra
Retrieve dichotomous key for Mammillaria
Overlay Consortium of California Herbaria specimen data by county on this map
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