Knot-stem bastard-sage

Eriogonum nodosum Small, Bull. Torrey Bot. Club 25: 49. 1898; E. pringlei J. M. Coulter & E. M. Fischer; E. trachygonum Torrey ex Bentham subsp. pringlei (J. M. Coulter & E. M. Fischer) S. Stokes; E. wrightii subsp. pringlei (J. M. Coulter & E. M. Fischer) S. Stokes; E. wrightii var. pringlei (J. M. Coulter & E. M. Fischer) Reveal

Shrubs, 3-10 × (3-)5-15 dm, densely tomentose to lanate. Leaf blades oblanceolate to narrowly elliptic, 0.8-1.2 × 0.25-0.5(-0.9) cm. Inflorescences open; branches slender or stout. Involucres 0.7-2.5 mm. Flowers 1-4 mm; perianth white to pink or rose. Achenes 1-3 mm.

Flowering Aug-Feb. Gravelly to rocky soils, mixed grassland, saltbush, creosote bush, and mesquite communities, scattered juniper woodlands; 100-1600 m; Ariz., Calif.; Mexico (Baja California, Sonora).

In the strict sense, var. pringlei differs from var. nodosum by its smaller (1-1.5 versus 3-4 mm) flowers, involucres (0.7-2 versus 1.5-2.5 mm), and achenes (1-1.5 versus 2-3 mm); also, the inflorescence branches of var. pringlei are more numerous and much more slender than those of var. nodosum. In the flora area, var. pringlei seems to be restricted to southwestern Arizona (La Paz, Maricopa, Pima, and Pinal counties) and is rare. It occurs also in northwestern Sonora, Mexico, where it is locally common. Variety nodosum is infrequent in California (Imperial, Riverside, San Bernardino, and San Diego counties) and northern Baja California, Mexico; it appears to be the common expression of the species in Yuma County, Arizona, rather than var. pringlei. Until adequate fieldwork is done on this complex, the uncertainty about var. nodosum (s. lat.) must remain. The varietal epithet nodosum has priority over pringlei by virtue of the autonym established by the publication of E. nodosum var. jaegeri Munz & I. M. Johnston.