Anulocaulis annulatus (Coville) Standl.

Herbs, stout perennial. Stems 0.5-2 m. Leaves: 4-6 pairs proximal to inflorescence; petiole 1-7 cm; blade broadly ovate to almost reniform, 2-10 × 2-9.5 cm, base broadly rounded to truncate or cordate, apex rounded to broadly obtuse, adaxial surface yellow-green, abaxial surface much paler, both surfaces moderately villous-hirsute, hairs with dark brown to blackish pustulate bases. Flowers 5-15 in umbel-like clusters on branches of inflorescence; perianth 9-10 mm, tube very pale pink to rose-pink, densely shaggy-hairy, limbs very pale pink to rose-pink, gradually flared; stamens 3, exserted 1-2 mm. Fruits broadly fusiform, 3.5-6 × 2.1-2.7 mm, not secreting mucilage when wetted; ribs 10, well defined, linear, low, narrow; equatorial ridge absent or occasionally low, linear, and incomplete. 2n = 24.

Calif.

Flowering late winter-late summer, occasionally mid fall.

Dry, gravelly outwash fans, talus slopes, roadsides; 70-1200m.

Boerhavia annulata Coville, Contr. U.S. Natl. Herb. 4: 177, plate 18. 1893

Anulocaulis annulatus (Coville) Standley, Contr. XL S. Nat
Herb. 12: 375. 1909.
Boerhaavia annulala Coville, Contr. U. S. Nat. Herb. 4: 177. 1893.
Plants erect from a decumbent base, 5-10 dm. high, sparsely branched below, loosely paniculate above, the branches stout, glaucescent, at least below, glabrous except at the villous nodes; petioles stout, 2-4 cm. long; leaf-blades broadly oval to ovate-oval or ovate-deltoid, 3-8 cm. long, 2-6 cm. wide, subcordate or rounded at the base and subequal, rounded at the apex or rarely only obtuse, coriaceous, shallowly and irregularly repand-dentate, yellowishgreen above and hirsute with slender hairs having dark enlarged glandular bases, paler beneath and densely hirsute with similar hairs; inflorescence nearly naked, the branches slender, the flowers in dense many-flowered headlike long-pedunculate umbels; bracts short, lanceolate, hirsute, the hairs with glandular bases; perianth 8 mm. long, greenish, the tube stout, longvillous, gradually dilated into a campanulate limb; stamens 3, short-exserted; fruit biturbinate, 5 mm. long, glabrous.
Type locality: Furnace Creek Canyon, Funeral Mountains, Inyo County, California.
Distribution: Inyo County, California.

Anulocaulis annulatus (Coville) Standley, Contr. U. S. Nat
Herb. 12: 375. 1909.
Boerhaavia annulata Coville, Contr. U. S. Nat. Herb. 4: 177. 1893.
Plants erect from a decumbent base, 5-10 dm. high, sparsely branched below, loosely paniculate above, the branches stout, glaucescent, at least below, glabrous except at the villous nodes; petioles stout, 2-4 cm. long; leaf-blades broadly oval to ovate-oval or ovate-deltoid, 3-8 cm. long, 2-6 cm. wide, subcordate or rounded at the base and subequal, rounded at the apex or rarely only obtuse, coriaceous, shallowly and irregularly repand-dentate, yellowishgreen above and hirsute with slender hairs having dark enlarged glandular bases, paler beneath and densely hirsute with similar hairs; inflorescence nearly naked, the branches slender, the flowers in dense many-flowered headtike long-pedunculate umbels; bracts short, lanceolate, hirsute, the hairs with glandular bases; perianth 8 mm. long, greenish, the tube stout, longvillous, gradually dilated into a campanulate limb; stamens 3, short-exserted; fruit biturbinate, 5 mm. long, glabrous.
Type locality: Furnace Creek Canyon, Funeral Mountains, Inyo County, California. Distribution: Inyo County, California.

Anulocaulis annulatus is a species of flowering plant in the four o'clock family known by the common name valley ringstem. It is endemic to the Mojave Desert of California, especially in the vicinity of Death Valley. This is a perennial herb growing a number of thin, erect stems sometimes exceeding a meter in height from a thick caudex.

The smooth stems have darkened internodes at intervals which are glandular and sticky. The leaves are mostly located at the base of the plant. Each has a short petiole and a thick, bumpy blade up to 10 centimeters wide. The leaf is coated in large, stiff hairs with glandular bases. The branching inflorescence bears clusters of very hairy, tubular flowers. Each flower is just under a centimeter long with a greenish throat and a striped pink face. The fruit is a small, hard body about half a centimeter long.