Duration: Annual

Nativity: Native

Lifeform: Forb/Herb

General: Annual herb with stems prostrate to decumbent or rarely ascending, 10-60 cm long, herbage appressed canescent-pubescent or rarely hirsute or glabrate in age.

Leaves: Opposite, pinnate leaves 2-6 cm long with 3-5 pairs of leaflets; leaflets sessile, broadly elliptic, 1-5 mm broad, 4-10 mm long, obtuse or rounded at apex, obliquely obtuse at base, strigose-canescent or tardily glabrate above; stipules linear-subulate to ovate, 1-3 mm long, usually early-deciduous.

Flowers: Yellow, solitary in leaf axils, on slender pedicels 1.5 cm long or less; sepals narrowly lance-ovate, 3-4 mm long, deciduous before the fruit matures; petals 3-5 mm long, yellow.

Fruits: Capsule 3-5 mm in diameter, 3 mm high, puberulent; carpels with low rounded, dorsal tubercles, often to 1.5 mm long, strongly reticulate on sides; topped with a beak 3-4 mm long, glabrous or nearly so, conic at base.

Ecology: Found on sandy or gravely flats below 7,000 ft (2134 m); flowers May-October.

Distribution: CA to TX, south to n. MEX

Notes: Kallstroemia is a genus of prostrate, annual herbs with opposite, even-pinnate leaves, 5-petaled flowers on pedicels emerging from the leaf axils, and 10-lobed fruits that split into 10 reticulate nutlets at maturity. The style persists as a cap or beak on the top of the fruit until it splits into nutlets. Sister genus Tribulus appears quite similar in growth form, but the fruits split into 5 spiny nutlets at maturity. K. californica differs from other Kallstroemia by having sepals that fall off before the fruit matures, smaller 3-5 mm petals, and being glabrous or sparsely hairy with appressed hairs.

Ethnobotany: The root was used to fight diarrhea and a poultice of chewed leaves was applied to sores or swellings.

Etymology: Kallstroemia is named for Anders Kallstrom (1733-1812) a contemporary of Giovanni Antonio Scopoli, the author of the genus; californica means of or from California.

Synonyms: Kallstroemia brachystylis, K. californica var. brachystylis

Editor: SBuckley 2010, AHazelton 2015