Plant: Subshrub; 1-4 dm tall
Leaves: opposite, puberulent, broadly ovate to elliptic, 15-30 mm long, 4-20 mm broad
Flowers: white, showy, vespertine; axillary; corolla funnelform; calyx lobes linear-lanceolate, subequal, 3-7 mm long; corolla hairy externally, 35-75 mm long, the tube 10-25 mm long, the throat 10-25 mm long, the lobes ovate, 10-25 mm long; stamens borne at the base of the throat
Fruit: pair of follicles, 5-13 cm long; SEEDS minutely reddish puberulent, flat, with the margins folded in forming a ventral groove, the tuft of hairs copper-colored
Misc: Rocky slopes and plains in desert grassland, often on limestone; 1150-1750 m (3700-5800 ft); Jun-Aug
REFERENCES: McLaughlin, Steven, P. 1994. Apocynaceae. J. Ariz. - Nev. Acad. Sci. Volume 27, 164-168.
Duration: Perennial
Nativity: Native
Lifeform: Subshrub
General: Low, suffrutescent forb to subshrub with puberulent stems, 10-40 cm tall; plants with milky sap.
Leaves: Opposite and sessile to short-petiolate; blades puberulent, broadly ovate to elliptic, 1.5-3 cm long, to 2 cm broad.
Flowers: White and showy, solitary or in clusters of 2 or 3 in leaf axils and branch tips; corolla funnelform, opening only at night (vespertine), hairy externally, 3.5-7.5 cm long, the tube 1-2.5 cm long, the throat 1-2.5 cm long, lobes ovate, 1-2.5 cm long; calyx lobes linear-lanceolate, subequal, 3-7 mm long; stamens borne at the base of the throat.
Fruits: Follicles (capsules splitting open along a single suture line) 5-13 cm long; seeds flat, minutely puberulent with reddish hairs, tipped with a tuft of copper-colored hairs.
Ecology: Found on rocky slopes and on the plains in the desert grasslands; 3,500-6,000 ft (1067-1829 m); flowers June-August.
Distribution: s NM, se AZ; south into n MEX.
Notes: Distinguished by a low-growing habit; often reddish stems; milky sap; opposite leaves, which are often noticeably leathery in texture; beautiful white funnel-shaped flowers with long tubes that stay open only a little while in the morning; the fruit is a pair of erect capsules, appearing as two long, round, linear prongs. Nomenclature appears to be in flux with this species, with some indicating it should now be named Mandevilla brachysiphon. It appears to be that the names are united through the basionym of Echites brachysiphon, which is indicated to be a Mexican taxon.
Ethnobotany: Unknown, but other species in the genus have uses.
Etymology: Macrosiphonia comes from macro, meaning large, and sipho, or tube, while brachysiphon means short-tube.
Synonyms: None
Editor: SBuckley 2010, FSCoburn 2014, AHazelton 2015
