Directory       News       Site Map       Home
         
    Jepson eFlora: Taxon page
Key to families | Table of families and genera

Previous taxon Indexes to all accepted names and synonyms:
| A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
Previous taxon

BRASSICACEAE (Cruciferae) MUSTARD FAMILY

Ihsan A. Al-Shehbaz, except as noted

Annual to shrub; sap pungent, watery. Leaf: generally simple, alternate; generally both basal, cauline; stipules 0. Inflorescence: generally raceme, generally not bracted. Flower: bisexual, generally radial; sepals 4, generally free; petals (0)4, forming a cross, generally white or yellow to purple; stamens generally 6 (2 or 4), 4 long, 2 short (3 pairs of unequal length); ovary 1, superior, generally 2-chambered with septum connecting 2 parietal placentas; style 1, stigma entire or 2-lobed. Fruit: capsule, generally 2-valved, "silique" (length >= 3 × width) or "silicle" (length < 3 × width), dehiscent by 2 valves or indehiscent, cylindric or flat parallel or perpendicular to septum, segmented or not. Seed: 1–many, in 1 or 2 rows per chamber, winged or wingless; embryo strongly curved.
± 330 genera, 3780 species: worldwide, especially temperate. [Al-Shehbaz et al. 2006 Plant Syst Evol 259:89–120] Highest diversity in Mediterranean area, mountains of southwestern Asia, adjacent central Asia, western North America; some Brassica species are oil or vegetable crops; Arabidopsis thaliana used in experimental molecular biology; many species are ornamentals, weeds. Aurinia saxatilis (L.) Desvaux in cultivation only. Aubrieta occasional waif in central North Coast Ranges, Carrichtera annua (L.) DC. in South Coast, Iberis sempervirens L., Iberis umbellata L. in Peninsular Ranges, Teesdalia coronopifolia (Bergeret) Thell., Teesdalia nudicaulis (L.) W.T. Aiton in southern Outer North Coast Ranges, Central Coast. Cardaria, Coronopus moved to Lepidium; Caulostramina to Hesperidanthus; Guillenia to Caulanthus; Heterodraba to Athysanus; California taxa of Lesquerella to Physaria; Malcolmia africana to Strigosella. —Scientific Editors: Douglas H. Goldman, Bruce G. Baldwin.

Key to Brassicaceae

DESCURAINIA TANSY MUSTARD
Annual, biennial (perennial herb); hairs minute, many-branched, tree-like, occasionally mixed with fewer simple hairs, club-shaped glandular papillae occasionally present. Stem: generally branched distally. Leaf: petioled, finely 1–3-pinnately lobed or divided, basal generally early-deciduous; cauline similar to basal, less divided distally on stem, base not lobed. Inflorescence: elongating. Flower: sepals erect to spreading, base not sac-like; petals obovate, yellow [± white]. Fruit: silique or silicle, dehiscent, linear, oblong, club-shaped, ellipsoid, or obovoid, not flattened, unsegmented; stigma entire. Seed: 5–100, in 1 or 2 rows, ellipsoid to oblong, plump; wing 0.
45–47 species: Eurasia, especially North America and South America, Canary Islands. (F. Descourain, French botanist, 1658–1740) May be TOXIC to livestock. [Detling 1939 Amer Midl Naturalist 22:481–520] Taxonomically difficult, most characters highly variable.
Unabridged note: A taxonomically difficult genus due to extensive variation and continuity in most characters. The extensive interspecific hybridization, polyploidy, fertility among species, weedy tendencies of hybrids and parents, and lack of reliable morphological characters make it difficult to delimit taxa. Numerous infraspecific taxa have been recognized, but without extensive cytological, molecular, and experimental studies, recognition of narrowly defined taxa is neither practical nor useful.

Key to Descurainia

D. incana (Fisch. & C.A. Mey.) Dorn
NATIVE
Biennial, hairy, canescent to ± green (glandular). Stem: erect, simple proximally, many-branched distally, (1.5)2.5–12 dm. Leaf: basal, proximal cauline 1.5–10(13) cm, widely lanceolate to oblanceolate or ovate, 1-pinnately lobed; ultimate segments linear to oblong or lanceolate, 3–10(15) mm, entire; distal cauline smaller, lobes narrower. Flower: sepals 1–1.8 mm, ± yellow; petals 1.2–2 mm, oblanceolate. Fruit: erect, appressed, (4)5–10(15) mm, 0.7–1.2(1.5) mm wide, linear, straight; valves glabrous; septum midveined; style 0.1–0.4 mm; pedicel erect to erect-ascending, 2–8(11) mm, straight. Seed: 14–22, in 1 row, 0.8–1.2 mm, ellipsoid to narrowly oblong.
2n=14,28. Open sites, meadows, sagebrush scrub, open aspen groves, roadsides; 100–3500 m. Klamath Ranges, Sierra Nevada, San Bernardino Mountains, Great Basin Floristic Province; to Alaska, Wyoming, New Mexico, Quebec, northeastern United States. May–Sep [Online Interchange]
Unabridged synonyms: [Descurainia richardsonii (Sweet) O.E. Schulz, illeg.; Descurainia richardsonii subsp. viscosa (Rydb.) Detling]

Previous taxon: Descurainia californica
Next taxon: Descurainia incisa subsp. incisa

Contact/Feedback

Name search

Citation for the whole project: Jepson Flora Project (eds.) 2013. Jepson eFlora, http://ucjeps.berkeley.edu/IJM.html, accessed on Dec 20 2014
Citation for this treatment: [Author of taxon treatment] 2013. Descurainia, in Jepson Flora Project (eds.) Jepson eFlora, http://ucjeps.berkeley.edu/cgi-bin/get_IJM.pl?tid=22609, accessed on Dec 20 2014

Copyright © 2014 Regents of the University of California
We encourage links to these pages, but the content may not be downloaded for reposting, repackaging, redistributing, or sale in any form, without written permission from The Jepson Herbarium.


Geographic subdivisions indicated for the distribution of Descurainia incana Markers link to CCH specimen records. If the markers are obscured, reload the page [or change window size and reload]. Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues.
READ ABOUT YELLOW FLAGS
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).

View elevation by latitude chart
Data provided by the participants of the Consortium of California Herbaria.
View all CCH records

 

CCH collections by month

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