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Draba standleyi
(Standley's whitlowgrass)

[taxon report][distribution map][all photos][line drawing]



Family: Brassicaceae

Scientific Name: Draba standleyi J.F. Macbride & Payson

Synonyms: Draba chrysantha S. Watson var. gilgiana (Wooton & Standley) O.E. Schulz; Draba gilgiana Wooton & Standley 1913, not Muschler 1906

Vernacular Name: Standley's whitlowgrass

R-E-D Code: 2-1-2

Description: Tufted perennial; caudex simple or closely branched, thick with marcescent (withered but persistent) leaf bases; stems few, 1-3 dm long, very slender, erect to partially decumbent, simple or few-branched, sparsely pubescent below with simple or forked trichomes, glabrous above or glabrous throughout; basal leaves narrowly oblanceolate, long-petioled, entire or remotely denticulate, pubescent to merely ciliate with stiff appressed hairs or glabrous, 1.5-8 cm long, stem leaves 1-8, small, remote, sessile but not auriculate, few-toothed or entire; inflorescences much elongated, 5- to 20-flowered; petals 4, yellow; fruiting pedicels erect to divaricately ascending, 8-13 mm long; siliques linear-elliptic to oblong, glabrous or nearly so, flat or contorted, 8-12 mm long; styles 1-2 mm long. Flowers June to August.

Similar Species: Draba standleyi is apparently most similar to D. petrophila, which is endemic to southeastern Arizona and adjacent northern Sonora (and perhaps southwestern New Mexico). It has also been confused with D. mogollonica, which can be distinguished by the characteristics in the table below. Both D. standleyi and D. petrophila are perennials with marcescent leaf bases. Both also have relatively long leaves and long styles in fruit. However, in D. standleyi the trichomes of the leaves and stems are simple or wanting and the stem leaves are few and remote, whereas in D. petrophila the trichomes of the leaves and stems are mostly cruciform to dendritic and the stem leaves are several and usually overlapping.

Draba

LONGEVITY

CROWN/STEM

STEM TRICHOMES

BASAL LEAVES

CAULINE LEAVES

FRUITING PEDICELS

STYLES

mogollonica

annual/ biennial

tap rooted; no marcescent leaf bases

simple below; glabrous above

flat rosette; 4-9 cm long

1-3, reduced

widely spreading, 1-2 cm long

1-2.25 mm

petrophila

perennial

marcescent leaf bases; stems relatively stout

cruciform to dendritic

numerous; 3-8 cm long

3-30, usually overlapping

4-12 mm

1.5-3 mm

standleyi

perennial

marcescent leaf bases; stems very slender

simple or forked & glabrous above or all glabrous

tufted; 1.5-8 cm long

1-8, reduced, remote

erect to divaricately spreading, 8-13 mm

1-2 mm


Distribution: New Mexico, Doņa Ana (Organ Mountains), Otero, Sierra, and Socorro counties; Texas, Jeff Davis County, Davis Mountains; southern Arizona; Mexico, northwestern Coahuila.

Habitat: Igneous rock faces, bases of overhanging cliffs, clefts of porphyritic and andesitic rocks and soil; 1,675-1,980 m (5,500-6,500 ft).

Remarks: The known populations are widely disjunct. However, its habitat, volcanic cliffs, is not particularly rare in the region and the plant may be more common than presently understood.

Conservation Considerations: This plant grows in habitats that have few disturbances.

Important Literature (*Illustration):

MacBride, J.F. and E.B. Payson. 1918. Annals of the Missouri Botanical Garden 5:150.

Rollins, R.C. 1993. The Cruciferae of continental North America. Stanford University Press, Stanford, California.

Wooton, E.O. and P.C. Standley. 1913. Descriptions of new plants preliminary to a report upon the flora of New Mexico. Contributions from the U.S. National Herbarium 16(4):124. [type description, as Draba gilgiana]

Information Compiled By: David Bleakly, 1999

Agency Status:
Taxon USFWS State of NM USFS BLM Navajo Nation Natural Heritage NM Global Rank
Draba standleyiSoCSoC...S2G2G3


Photo credits in header Peniocereus greggii var. greggii © T. Todsen,
Lepidospartum burgessii © M. Howard, Argemone pleiacantha ssp. pinnatisecta © R. Sivinski
©2005 New Mexico Rare Plant Technical Council