Yavapai County Buckwheat

Eriogonum ericifolium is rare and localized, known only from the Verde River Valley of Yavapai County. The species is distinctive, yet some plants appear to approach E. microthecum var. simpsonii. The heather-leaf wild buckwheat is considered a “sensitive” species in Arizona and a candidate for federal protection.

Subshrubs, spreading and matted, not scapose, 0.5-1.5 × 0.8-2.5(-3) dm, mostly floccose or glabrous, greenish. Stems spreading, with persistent leaf bases, up to 1/ 4 height of plant; caudex stems absent or compact; aerial flowering stems spreading to erect, slender, solid, not fistulose, 0.03-0.1 dm, floccose to thinly tomentose. Leaves cauline, 1 per node or fasciculate; petiole 0.1-0.15(-0.2) cm, tomentose; blade linear, 0.6-1 × (0.08-)0.1-0.2 cm, densely white-tomentose adaxially, glabrous and green adaxially, margins revolute. Inflorescences umbellate-cymose to cymose, compact, 0.5-1 × 0.5-2 cm; branches usually dichtomous proximally, otherwise with secondaries suppressed, floccose or glabrous; bracts 3, scalelike, linear, 0.5-1.5 mm. Peduncles absent. Involucres 1 per node, turbinate, 1.5-3(-3.5) × 1-2 mm, floccose; teeth 5, erect, 0.4-0.6 mm. Flowers 2-3(-3.5) mm; perianth white to pink or rose, glabrous; tepals connate proximal 1/ 4, dimorphic, those of outer whorl obovate, 1.7-2 mm wide, those of inner whorl oblanceolate, 0.8-1 mm wide; stamens slightly exserted, 2-3 mm; filaments pilose proximally. Achenes light brown, 2-2.5 mm, glabrous except for papillate beak.

Ariz.

Flowering Aug-Nov.

Gravelly or rocky slopes of lacustrine silt, mixed grasslands, chaparral and oak-woodlands; 900-1100m.

Eriogonum mearnsii Parry; E. microthecum Nuttall subsp. ericifolium (Torrey & A. Gray) S. Stokes; E. microthecum subsp. mearnsii (Parry) S. Stokes