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Scientific Name: Streptanthus sparsiflorus Rollins
Vernacular Name: Guadalupe jewelflower
R-E-D Code: 2-1-2
Description: Annual, glabrous throughout; stems and leaves glaucous (bluish); stems 3-6 dm tall, simple below, branched from about 1 dm upward; leaves somewhat fleshy, greenish and minutely punctate above, slate-colored and nonpunctate below; lower stem leaves sessile, auriculate, lyrately pinnatifid to nearly runcinate, 8-12 cm long, 2-4 cm wide; leaves gradually reduced upward; upper stem leaves mostly entire, occasionally sinuate-dentate, ovate to broadly oblong, obtuse, auriculate and clasping the stem; inflorescence racemose, usually fewer than 10 flowers per raceme; flowers slightly zygomorphic; sepals straw-colored to pale purplish, not swollen, narrowly ovate, 9-11 mm long, about 2 mm wide, lateral sepals more narrowly tapered and thicker at tip than upper and lower sepals; petals showy, purplish, 15-18 mm long, blades 3-5 mm wide, reflexed at flowering; stamens 4, upper pair protruding beyond sepals, filaments 7-9 mm long, anthers 2.5-3 mm long, lower pair of stamens with anthers included, filaments 4-5 mm long, anthers 3-4 mm long, single stamens often with anthers longer than filaments; fruiting pedicels stout, terete, divaricately ascending, 5-10 mm long, strongly expanded at the summit; siliques subsessile, divaricately ascending, linear, obtuse to somewhat acute above and below, strongly flattened parallel to the plane of the septum, 4-7 cm long, 5-7 mm wide, valves with a central nerve from base to apex, septum translucent, entire, funicles winged; seeds flattened, widely wing-margined, orbicular, about 5 mm in diameter, wings uniform, 1-1.2 mm wide. Flowers May through June.
Similar Species: This species is unlikely to be mistaken for other Streptanthus in the area because of its large, showy flowers, sessile, auriculate, and pinnatifid to lobed lower stem leaves and wide siliques.
Distribution: New Mexico, Eddy County; adjacent Texas, Culberson County.
Habitat: Limestone canyon bottoms and montane scrub; 1,500-2,150 m (5,000-7,000 ft).
Remarks: Apparently endemic to the Guadalupe Mountains. This plant can be locally abundant, but is seldom collected. Little is known of its distribution and habitat requirements.
Al-Shebhaz and Mayer (2008) placed Streptanthus sparsiflorus in synonymy under S. platycarpus and it is published that way in Flora of North America, Volume 7 (2010). Unpublished genetic data from Alan Pepper of Texas A&M University (pers. comm. 2011) indicates S. sparsiflorus is a distinct species. In discussions at the 2011 New Mexico Rare Plant Technical Council Meeting, Council members concluded there is sufficient uncertainty about the correct placement of S. sparsiflorus that it should be retained as a distinct species while additional information is being gathered.
Conservation Considerations: Most habitats for this plant are very rugged and remote. Current land uses of livestock grazing and recreational hiking pose no threat to this species.
Important Literature (*Illustration):
Rollins, R.C. 1993. The Cruciferae of continental North America. Stanford University Press, Stanford, California.
Rollins, R.C. 1970. Notes on Streptanthus and Erysimum (Cruciferae). Contributions from the Gray Herbarium 200:190-195.
Flora of North America Editorial Committee. 2010. Flora of North America, volume 7. Oxford University Press, New York.
Al-Shehbaz, I.A. and M.S. Mayer. 2008. New and noteworthy Streptanthus (Brassicaceae) for the Flora of North America. Novon: A Journal for Botanical Nomenclature from the Missouri Botanical Garden 18:279-282.
Information Compiled By:
David Bleakly, 1999; last updated, 2011