U.S. DEPARTMENT OF THE INTERIORBUREAU OF LAND MANAGEMENT
 
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Williams's Combleaf
(Polyctenium williamsiae )
Brassicaceae
William's combleaf; Photo Copyright James Morefield NNHP
Photo Copyright James Morefield NNHP

Description: Low growing perennial herb (forb) from a buried woody taproot; underground stems loosely to densely branched. Stems widely spreading (decumbent) often branched and up to 4 1/16 inches (1.3 dm) tall. Herbage sparsely to densely pubescent and dark to grayish or glaucous green.  Pinnately divided alternate leaves, to 1/2 to 3/4 inches (1.3-1.8 cm) long, not or shortly stalked, pubescent with stiffly branched hairs; dense below becoming less crowded and smaller upward.  Pubescent inflorescence congested and corymbose, somewhat elongate in fruit.  Four white to pinkish petals, oval to spoon shaped, 1/16 to 1/8 inch (2-4 mm) long. Fruit a silicle 1/8 to 1/4 inch (3-6.5 mm) long and 1/16 to 3/32 inches (1.3-2.5 mm) wide.

Distribution: Great Basin from Mineral Co, NV and adjacent Mono Co, CA north to the CA-NV line in Washoe Co.  Reported from NE CA at Mud Flat and the Madeline Plains (Lassen Co) and into SE OR.

Habitat: Barren sandy to sandy-clay or mud margins & bottoms of non-alkaline seasonal lakes & playas perched over siliceous volcanic bedrock in silver sagebrush, mountain big sagebrush and juniper woodlands between 4,215 and 8,935 feet (1,285-2,725

Flowering Period: (April) May to June (dependent on seasonal precipitation and temperature). Similar Plants: P. fremontii but that has a longer linear to narrowly oblong fruit (silque) ¨ù - ¨ý inches ([5]7-16 mm) long to 4/5 to 1/25(1/16) inches (1-1.7[2] mm) wide.  The longest petals on P. williamsiae are 2-4 mm long and on P. fremontii they are 4-6 mm long.

 Status: BLM Sensitive, California Native Plant Society List 1B.2; Nevada Native Plant Society Threatened; Nevada critcally endangered.

 

 

Field Office: Eagle Lake, Alturas, Surprise

 
Last updated: 08-05-2010