Plant: perennial herb, woody taproot; stems suffrutescent, erect to almost decumbent, usually branched, appressed-pubescent to hirsute to sericeous
Leaves: elliptic to lanceolate or ovate-lanceolate, entire, 3-10 mm long, 1-4 mm wide, usually acute on both ends, sometimes obtuse basally, with indumentum as on stems; petioles to 2 mm long
INFLORESCENCE: usually of solitary flowers concentrated in upper leaf axils
Flowers: sepals 3-4.5 mm long, 2-3 mm wide, equal or the inner ones slightly longer, the margins scarious, the outer sepals pubescent throughout, the inner sepals pubescent only at apex; corolla white, 5-6.5 mm long
Fruit: FRUITS unilocular, 4-valvate, ovoid, 5-6 mm long, brown, apically pubescent. SEEDS 3-4 mm long, glabrous
Misc: Alkaline ponds, marshes, lakes, and cultivated fields; 50-1200 m (100-4000 ft); May-Nov
REFERENCES: Austin, Daniel F. 1998. J. Ariz. - Nev. Acad. Sci. Convolvulaceae 30(2): 61.
Duration: Perennial
Nativity: Native
Lifeform: Forb/Herb
General: Perennial herb, 5-30 cm tall, from a woody taproot; stems woody at the base, erect to almost decumbent and much-branched from the base; herbage appressed-pubescent, hirsute, or sericeous.
Leaves: Alternate along the stems on short petioles up to 2 mm long; blades elliptic to lanceolate or ovate-lanceolate, 3-10 mm long and 1-4 mm wide, usually acute on both ends but sometimes obtuse basally, with entire margins.
Flowers: Small and white, solitary in the leaf axils near branch tips; sepals 5, ovate, 3-4 mm long, hairy; corolla white, funnel-shaped with 5 spreading lobes at the top, the corolla tube 4 mm long and the lobes 2-3 mm long.
Fruits: Capsule ovoid, 5-6 mm long, brown, hairy near the top; containing 1 seed (occasionally up to 4 seeds), 3-4 mm long.
Ecology: Found at the margins of alkaline ponds, marshes, lakes, and cultivated fields, below 4,000 ft (1219 m); flowers May-November
Distribution: CA and OR, east to ID, UT, NM, OK, and TX; south to S. Amer.
Notes: This small perennial commonly has a low and spreading growth form in the southwest. Look for the small, silvery-hairy, oval-shaped leaves lining the stems; and in the leaf axils find the small white flowers with funnel-shaped corollas topped with 5 usually pointed lobes. The species superficially resembles Evolvulus nuttalianus with its small hairy leaves, low, branching growth form, and funnel-shaped flowers in the leaf axils; however E. nullalianus has larger, lavender flowers 5-9 mm long, with narrower, lanceolate to linear sepals (C. truxillensis has small white flowers 4 mm long with oval-shaped sepals). Look for it in moist, alkaline environments.
Ethnobotany: Unknown, but other species in the genus have uses.
Etymology: Cressa is the Greek word referring to a woman from Crete; truxillensis means from Trujillo, in Peru.
Editor: AHazelton 2017
