Draba standleyi (Standley's Whitlow-Grass)

Photograph by Patrick Alexander at polyploid.net (2009)

Family

BRASSICACEAE

Scientific Name with Author

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

Common Name

Standley's Whitlow-Grass

Agency Status
USFWS	State of NM	USFS	BLM	Navajo Nation	State Rank	Global Rank	R-E-D Code	NMRPTC Status	Strategy Status
					S2	G2G3	2-1-2	R	SS

Rare Plant Conservation Scorecard Summary
Overall Conservation Status	Documented Threats	Actions Needed
UNDER CONSERVED	Fire & fire suppression	document rarity

To download the Scorecard click here.

Counties

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, Dona 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

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

For distribution maps and more information, visit Natural Heritage New Mexico