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Howell's Thelypodium
(Thelypodium howellii var. howellii )

Howell's Thelypodium; Photo Copyright 1990 Dean Wm. Taylor
Photo Copyright 1990 Dean Wm. Taylor

Description: Biennial herb with stem 4-36 inches (1-9 dm) tall, and branched above. Leaves primarily basal in a rosette, oblanceolate, and 3/4 - 4 inches (2-10 cm) long. Cauline leaves have petioles and are clasping, sometimes lobed (auriculate). Petals are spoon-shaped, lavender to purple, 1/16 inch (0.5-1.2 mm) wide and ¨ü to 9/16 inches (9 to 14 mm) long.  Sepals are oblong, purplish, and 1/4 inch (7 mm) long. Petals are spoon-shaped, lavender to purple, and 1/16 inch (.5-1.2 mm) wide. Fruit are cylindric siliques, 5/8 - 1 3/4 inches (1.5-4.5 cm) long, with thick, brown seeds. 

Distribution: Modoc Plateau and Warner Mountains, Lassen, Modoc, & Shasta counties; south central-central Oregon into sc Washington

Habitat: Moist alkaline soils, open, wet to dry meadows and marshes.  3,900 to 5,090 feet (1,200 to 1,550 m).

 Flowering Period: Late May-early/mid August

Similar Plants: T. integrifolium but that species has sessile leaves that are entire and the flowers (sepals and petals) are smaller (2.3-4.8 mm and 4.5-9 mm).

 Status: BLM Sensitive, California Native Plant Society List 1B.2; federal species of concern


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Field Office: Eagle Lake

Last updated: 08-05-2010