Great Basin Naturalist Volume 37 Number 3 Article 1 9-30-1977 Utah flora: Brassicaceae (Cruciferae) Stanley L. Welsh Brigham Young University James L. Reveal University of Maryland, College Park, and Smithsonian Institutuion, Washington, D.C. Follow this and additional works at: https://scholarsarchive.byu.edu/gbn Recommended Citation Welsh, Stanley L. and Reveal, James L. (1977) "Utah flora: Brassicaceae (Cruciferae)," Great Basin Naturalist: Vol. 37 : No. 3 , Article 1. Available at: https://scholarsarchive.byu.edu/gbn/vol37/iss3/1 This Article is brought to you for free and open access by the Western North American Naturalist Publications at BYU ScholarsArchive. It has been accepted for inclusion in Great Basin Naturalist by an authorized editor of BYU ScholarsArchive. For more information, please contact [email protected], [email protected]. The Great Basin Naturalist Published at Provo, Utah, by Brigham Young University ISSN 0017-3614 Volume 37 September 30, 1977 No. 3 UTAH FLORA: BRASSICACEAE (CRUCIFERAE) Stanley L. Welsh' James L. Reveal- Abstract.— The mustard family, Brassicaceae (Cruciferae) is revised for the state of Utah. Treated are 155 spe- cies and 44 varieties, including 37 species of introduced weeds or escaped cultivated plants. A key to the genera and species is included, along with detailed descriptions, distribution data, and pertinent comments for many of the taxa. Proposed new varieties are: Lepidium montanum Nutt. var. stellae Welsh & Reveal; L. montanum var. neeseae Welsh & Reveal; Lesquerella hemiphysaria Maguire var. liicens Welsh & Reveal; Physaria aciitifolia Rydb. var. purpurea Welsh & Reveal; and, Tfielypodhtm sagittatum (Nutt.) Endl. in Walp. var. vennicularis Welsh & Reveal. The following new combinations are made: Arabis confinis S. Wats. var. interposita (Greene) Welsh & Reveal; Descurainia pinnata (Walt.) Britt. var. paysonii (Detl.) Welsh & Reveal; D. richardsonii (Sweet) O. E. Schulz var. brevipes (Nutt.) Welsh & Reveal; Draba asprella Greene var. zionensis (C. L. Hitchc.) Welsh & Reveal; Draba densifolia Nutt. ex Torr. & Gray var. daviesiae (C. L. Hitchc.) Welsh & Reveal; Lesquerella alpina (Nutt.) S. Wats. var. parvula (Greene) Welsh & Reveal; Lesquerella kingii S. Wats. var. parvifolia (Maguire & Holmgren) Welsh & Reveal; Rorippa islandica (Oed.) Borbas var. glabra (O. E. Schulz) Welsh & Reveal; Thelypo- diopsis divaricata (Rollins) Welsh & Reveal; Thelypodium integrifolium (Nutt.) Endl. var. affine (Greene) Welsh & Reveal. This paper, dealing with the Brassicaceae, There are 155 species and 44 varieties. Ad- is one of a series of proposed revisions ventive weedy species and cultivated plants which will result ultimately in a definitive known to escape and persist constitute 37 treatment of the flora of Utah. Not since species and two varieties. Thus, almost 20 the work of Tidestrom (1925) has the family percent of the taxa included are introduced, been treated in its entirety, although a par- It is unlikely that any of the other large tial treatment is to be found in the work by families of vascular plants in Utah, such as Welsh and Moore (1973). The family has Asteraceae, Poaceae, Fabaceae, or Rosaceae not been neglected by monographers, how- will contain such a large proportion of ever. That observation is supported by the weedy and adventive taxa. numerous references listed following the ge- Generic limits in this family are often dif- neric descriptions in the taxonomic treat- ficult to define, and because of this well- ment. known problem, some taxa have been The family is both large and tax- shifted from one genus to another, or even onomically complex. In the present treat- among several genera, depending on the au- ment, some 199 taxa are recognized as oc- thority one chooses to follow. One author, curing (or probably occuring) in Utah. Krause, writing in Sturm's Flora von 'Department of Botany and Range Science, and Life Science Museum, Brigham Young University, Provo, Utah 84602. 'Departments of Botany, University of Maryland, College Park, Maryland 20742, and National Museum of Natural History, Smithsonian Institution, Washington, DC. The support provided by National Science Foundation grant BMS 75-13063 is acknowledged. The work reported here was conducted while on sabbatical leave to Brigham Young University from January to July 1976. 279 280 Great Basin Naturalist Vol. 37, No. 3 Deutchland in 1902, proposed an inclusive summarize all features, our understanding of genus, Crucifera, for plants treated in this the genera in this family will remain con- paper as belonging to Conringia, Diplotaxis, fused. Erysimum, Brassica, Lepidium, Hesperis, Genera and species, in the present treat- Draba, Barbarea, Hutchinsia, Baphanus, Si- ment, are arranged alphabetically. The key symbrium, and Thlaspi. Such an approach is to genera is divided into seven different, even more frustrating than treating taxa morphologically based subkeys. These arti- with obscure taxonomic limits; it is neither ficial subkeys provide leads to groups of realistic nor is it practical. species or individual taxa within the various In the Utah flora, problems of generic genera. limits fall mainly within the purportedly primitive members of the family, such as Literature Gited Streptanthus, Thelypodium, Tlielypodiopsis, Caulanthus, Chlorocrambe, and Sisymbrium. Holmgren, P. K., and W. Keuken. 1974. Index her- barionim-I. Edition 6. Regnum Veg. 92: 1-397. The approach taken herein is somewhat Lawrence, G. H. M., A. F. G. Buchheim, G. S. conservative, as we have tended to accept Daniels, and H. Dolezal. 1968. B-P-H, Bo- the various genera which appear to be tanico-Periodicum-Huntianum. Pittsburgh: Hunt more or less distinct, not only in Utah, but Botanical Library. 1063 pp. Stafleu, F. a., and R. S. Cowan. 1976. Taxonomic in other western states as well. Even so, the literature. Volume 1: A-G. Regnum Veg. 94: 1- species treated in Caulanthus not appear do 1136. to represent a natural group, and some spe- TiDESTROM, I. 1925. Flora of Utah and Nevada. Contr. cies of Tlielypodiopsis appear to be more U.S. Natl. Herb. 25: 1-665. closely related to taxa in other genera, espe- Welsh, S. L., and G. Moore. 1974. Utah plants, Tracheophyta. Provo: Brigham Young University cially in Thelypodium, than they are to Press. 474 pp. each other. The species in Caulanthus seem to show affinities to Thelypodium, Tlielypo- diopsis, Chlorocrambe, and Streptanthus. Brassicaceae Burnett In large part, we have tended to follow Mustard Family the published opinions of Dr. Reed C. Roll- Annual to perennial herbs or rarely suf- ins of Harvard University, long-time student frutescent, often with a pungent watery of the family, but we feel that much more juice, glabrous to pubescent with simple or work -is needed in ascertaining relationships more commonly branched to stellate hairs, and hope that students will investigate some often glaucous; leaves alternate or basal and of the more difficult elements in the future. still alternate, entire or lobed, simple to Some solutions might be forthcoming from compound, exstipulate, the cauline leaves studies of fine structure in various mor- usually sessile and auriculate; flowers per- phological features of the species, especially fect, regular or nearly so, hypogynous, those to be derived from pollen mor- borne in ebracteate or rarely bracteate phology, from a review of phytochemistry racemes, spikes, or corymbs, rarely solitary beyond that which has already been done, and terminal on leafless scapes; sepals 4, and from a detailed review of cytology of erect to somewhat spreading, greenish to the troublesome genera. colored, the outer 2 often somewhat bulged Continued reliance upon floral and fruit- or saccate at the base; petals 4, rarely lack- ing characteristics, features upon which taxa ing, yellow, white, or pink to blue or have been and are currently based, is a part purple, commonly clawed, the blade of the problem of arriving at a realistic sys- rounded to occasionally bilobed and spread- tem of classification of genera. An entity ing in the form of a cross (hence Cruci- represents the sum of its features; yet in the ferae); stamens 6 with the outer 2 in.serted Brassicaceae, much emphasis, sometimes to lower and shorter than the other 4 (tetrady- the exclusion of other features, has been namous), rarely 4 or 2; nectar glands com- placed on features of flowers and fruit, and, monly 4; ovary superior, 2-loculed or, less until work is directed toward an attempt to commonly, only 1-loculed, usually with a Sept. 1977 Welsh, Reveal: Utah Flora, Brassicaceae 281 thin partition (replum) between the two the repkiin or, less commonly, flattened marginal placentae from which, when ma- contrary to the replum; seeds (1) 2 to sever- ture, the valves usually separate, the stigma al in a single row per locule (uniseriate) or rather small, entire to shallowly 2-lobed; more or less distinctly arranged in 2 rows fruit usually nonstipitate but occasionally so (biseriate), smooth to striate or pitted and with a slender stipe, typically dehiscent or plump to flattened or even wing margined, if indehiscent then constricted between the exalbuminous. seeds (tonilose) and sometimes breaking A large, worldwide family of perhaps 375 transversely, several times longer than broad genera and 3000 species, with many plants (silique) to much shorter and not more than of economic value as ornamentals, impor- 2 or 3 times as long as broad (silicle), the tant vegetables, or noxious weeds, sides flattened or compressed parallel with 1. Plants with cauline leaves both sessile and auriculate (at least some), or auriculate and petiolate (in some Barbarea, Nasturtiuyn, and Rorippa) 2 Plants without cauline leaves or with cauline leaves not auriculate and ses- sile, either petioled or merely sessile 4 2(1). Petals yellow; plants glabrous or with simple hairs, rarely with some mal- pighian hairs in Thelypodiopsis Key I Petals white, pink, lavender, chestnut, or purple, but not yellow (cream colored in Camelina and Arahis); plants glabrous or variously pubescent 3 3(2). Plants glabrous or with simple trichomes only Key II Plants pubescent with at least some malpighian, branched, or stellate hairs Key III 4(1).