|Jepson Flora Project: Jepson Interchange|
|TREATMENT FROM THE JEPSON MANUAL (1993)||
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Jepson Interchange (more information)
©Copyright 1993 by the Regents of the University of California
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Annual to subshrub
Leaves generally basal and cauline, alternate, generally simple; stipules 0
Inflorescence: generally raceme
Flower bisexual; sepals 4, free; petals (0)4, free, generally white or yellow, often clawed; stamens generally (2,4)6, generally 4 long, 2 short; ovary 1, superior, chambers generally 2, septum membranous, connecting 2 parietal placentas, style 1, stigma simple or 2-lobed
Fruit: generally capsule ("silique") with 2 deciduous valves, sometimes breaking transversely or indehiscent
Seeds 1many per chamber
Genera in family: 300+ genera, 3000+ species: worldwide, especially cool regions; some cultivated for food (especially Brassica, Raphanus ) and ornamental
Recent taxonomic note: Recently treated to include Capparaceae [Rodman et al. 1993 Ann Missouri Bot Gard 80:686699; Rollins 1993 Cruciferae of Continental North America. Stanford Univ Press]
Family description, key to genera by Robert A. Price.
TANSY MUSTARDAnnual, biennial, rarely per; hairs generally minute, generally multibranched, fewer simple, some glandular
Leaves 1many-pinnately lobed to compound; basal often rosetted but withering
Inflorescence elongating; bracts generally 0
Flower: petals < 3 mm, yellow or whitish, blades obovate, obtuse
Fruit linear to ± obovate, straight or uneven-margined, generally ± cylindric; style < 0.8 mm or 0, stigma generally head-like, entire
Seeds: 12 rows per chamber, generally < 1 mm, elliptic, plump, gelatinous when wet; wing 0; embryonic root at back of 1 cotyledon
Species in genus: ± 40 species: worldwide temp
Etymology: (F. Descourain, French botanist, 16581740)
Reference: [Detling 1939 Amer Midl Naturalist 22: 481520]
Relationships, characters of species difficult.
May be TOXIC to livestock.
D. obtusa (Greene) O.E. Schulz subsp. adenophora (Wooton & Standl.) DetlingBiennial, erect, coarse, whitish
Stem generally 1, simple or branched above
Leaf 16 cm, 1-pinnately lobed or -compound, canescent; hairs minute, multibranched, rarely glandular; lobes or leaflets 25 pairs, linear to oblanceolate, tip generally obtuse
Flower: sepals 22.5 mm, ± < petals, sparsely glandular; petals yellowish
Fruit 515 mm, linear, straight, generally glabrous; both ends tapered abruptly; pedicel ascending to spreading, 1225 mm, sparsely glandular
Seeds 2432 per chamber, 12 rows per chamber, closely packed, 0.71 mm
Ecology: Gravelly flats, open woods, lake margins
Elevation: 9002200 m.
Bioregional distribution: e Peninsular Ranges, Mojave Desert
Distribution outside California: to New Mexico, Baja California
Flowering time: MayJun
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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 Descurainia obtusa subsp. adenophora
Retrieve dichotomous key for Descurainia
Overlay Consortium of California Herbaria specimen data by county on this map
Show other taxa with the same California distribution | Read about bioregions | Get lists of plants in a bioregion
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