Baretwig Neststraw

Stylocline psilocarphoides is centered in the Mojave and western Great Basin deserts and extends to southeastern Oregon, southwestern Idaho, and through the western Sonoran Desert nearly to Mexico. Disjunct collections from southern Arizona in 1876 and 1941 are likely to be either labeling errors or from introductions that did not persist.

Circumscription of Stylocline psilocarphoides became clearer after recognition of S. intertexta and S. masonii (J. D. Morefield 1992b).

Plants 1–8(–18) cm (branches ± leafless between proximal forks). Leaves ± acute, mucronate, longest 8–18 mm; largest capitular leaves elliptic to spatulate, 3–10 × 1–2 mm. Heads in strictly dichasiform arrays, ovoid, largest 3.5–5 × 2.5–4 mm, thinly lanuginose. Phyllaries 0, vestigial, or falling, ± subulate, mostly 0.1–0.5 mm, unequal. Receptacles ± cylindric, 2–3 mm, heights 5–8 times diams.; scars concentrated proximally and distally, raised, peglike. Pistillate paleae: longest 2.8–3.3 mm, winged distally; wings oblanceolate to oblacrimate, widest in distal ¹/3 of palea lengths; bodies cartilaginous; outermost paleae open, concave. Functionally staminate florets 2–5; ovaries ± vestigial, 0.1–0.3(–0.4) mm; corollas 1.1–1.7 mm (lobes usually 5). Cypselae 1.1–1.6 mm, obcompressed; pappi: staminate rarely 0, usually of 1–3 smooth bristles 1.1–1.5 mm.

Stylocline psilocarphoides is a species of flowering plant in the family Asteraceae known by the common names baretwig neststraw and Peck's neststraw. It is native to the western United States from Idaho to southeastern California, where it grows in deserts and other dry, sandy, gravelly habitat. It is a small annual herb growing at ground level with stems measuring 1 to 18 centimeters in length. It is woolly or felt-like in texture with a coating of white hairs. The pointed leaves are up to 1.8 centimeters long and alternately arranged. The inflorescence bears oval flower heads no more than half a centimeter in diameter. The head generally has no phyllaries, or has small ones that fall away early. It is a hardened ball of several woolly white flowers.