Butterworth's Buckwheat

Eriogonum butterworthianum is a rare and localized species that grows in the cracks of Vaqueros sandstone near The Indians in the Santa Lucia Range of Monterey County. It is considered a “sensitive species” by the U.S. Forest Service. Its relationship to other species in subg. Eucycla is uncertain. Butterworth's wild buckwheat would make an elegant addition to the garden. Given its rarity, great care must be taken even in collecting seeds.

Subshrubs, rarely scapose, 1-3 × 1-4 dm, tomentose, grayish to reddish. Stems slightly spreading to erect, without persistent leaf bases, up to 1/ 4 height of plant; caudex stems absent; aerial flowering stems erect, slender, solid, not fistulose, 0.1-0.3 dm, tomentose.  Leaves sheathing up stem 0.5-1.5 cm, 1 per node; petiole 0.1-0.3 cm, tomentose; blade linear to narrowly elliptic, (0.5-)1-2 × 0.1-0.4 cm, grayish- to reddish-brown-tomentose, margins revolute. Inflorescences cymose-umbellate to cymose, rarely capitate, often with involucres racemosely disposed at tips, usually 1-2 × 1-2 cm; branches dichotomous, rarely scapelike, tomentose; bracts 3, scalelike, narrowly triangular, (1-)2-4(-5) mm. Peduncles absent. Involucres 1 per node, turbinate to turbinate-campanulate, (4-)5-6 × 3-4 mm, tomentose; teeth 5, erect, 1-2 mm. Flowers (3-)4-5 mm; perianth ochroleucous to rose, glabrous; tepals connate proximal 4, monomorphic, obovate; stamens exserted, 5-6 mm; filaments pubescent proximally. Achenes brown, 3-3.5 mm, glabrous.

Calif.

Flowering Jun-Sep.

Sandstone outcrops, chaparral communities, oak and conifer woodlands; of conservation concern; 600-700m.

Eriogonum butterworthianum is a rare species of wild buckwheat known by the common name Butterworth's buckwheat. It is endemic to the Santa Lucia Mountains of central Monterey County, California, where it is known from a few occurrences in the wilderness southeast of Big Sur in the vicinity of Junipero Serra Peak. Its native habitats include oak and conifer woodlands, chaparral communities, and sandstone outcrops. Eriogonum butterworthianum is a small clumpy shrub or subshrub that grows up to about 30 centimeters tall and wide. Leaves are 2 centimeters long and reddish-green in color. They are woolly, oval in shape, and curled under at the edges. The inflorescence is a cluster of flowers up to 2 or 3 centimeters wide. Each individual flower is a few millimeters wide and dull yellowish to pinkish in color. Flowers bloom June to September.