Duration: Annual

Nativity: Native

Lifeform: Forb/Herb

General: Diffuse annual herb with decumbent to ascending stems 10- 100 cm long, hirsute-hispid and also short-pilose.

Leaves: Opposite, pinnate leaves 4-12 cm long with 5-9 pairs of leaflets; leaflets sessile, obliquely oblong, 2-5 mm wide, 8-25 mm long, asymmetrical at base, usually glabrous above, glabrate or pubescent with both coarse and fine hairs beneath; stipules linear-subulate, 4-6 mm long.

Flowers: Orange and showy, solitary on pedicels from the leaf axils; pedicels 1-2 cm long at anthesis; sepals narrowly linear-lanceolate, 5 mm long, hirsute, persistent in fruit; petals 5, deep dark orange that fades to yellow with the day, narrowly obovate, 1.5 to 3 cm long; corolla center and filaments dark orange-red.

Fruits: Fruiting pedicels 3-7 cm; body of fruits 4-5 mm and knobby, topped with a columnar beak much longer than the body of the fruit, 8-12 mm long.

Ecology: Found on desert flats, gravelly or sandy soils; below 5,000 ft (1524 m); flowers February-September.

Distribution: s CA, AZ, NM, sw TX; south to 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 the fruit splits into nutlets. K. grandiflora has stiff, spreading hairs covering its herbage, showy orange flowers (petals 1.5- 3 cm long) that are much larger than other species in the genus, and fruits with long beaks (8-11 mm), which are twice as long as the nutlets and longer than other species in the genus.

Ethnobotany: Unknown, but other species in the genus have uses.

Etymology: Kallstroemia is named for Anders Kallstrom (1733-1812) a contemporary of Giovanni Antonio Scopoli, the author of the genus; grandiflora refers to the large flower.

Synonyms: None

Editor: SBuckley 2010, FSCoburn 2015, AHazelton 2015