Asclepias uncialis Greene
Family: Apocynaceae
wheel milkweed,  more...
Asclepias uncialis image
BLM  
Plant: Dwarf to low herbs; stems few to several from the root crown, loosely ascending to decumbent, mostly unbranched, 5-20 cm long, sparsely to densely covered with short curly hairs Leaves: erect or spreading, opposite to irregularly alternate, the petioles 1-5 mm long, the blades broadly ovate to lanceolate or linear-lanceolate, becoming progressively narrower upwards, 1-5 cm long, 1-25 mm broad, apically rounded or obtuse to mostly attenuate-acute, rounded to obtuse or acute at the base, the margins short woolly, the upper and lower surfaces short woolly to glabrous, the veins typically persistently pubescent INFLORESCENCE: UMBELS 1 to several, sessile to infrequently short-pedunculate, lateral at the upper nodes, more or less crowded, but (at least on older plants) not simulating a solitary, terminal inflorescence, 1-4 cm broad Flowers: small; calyx lobes 2-4 mm long; corolla purple, the lobes 3-6 mm long; hoods yellowish to pinkish, mostly erect, hemispheric to somewhat oblong, 1.2-2.1 mm long, 1-2.1 mm broad, the rim truncate with a more or less well developed pair of triangular marginal lobes, about as long as to 1 mm shorter than the gynostegium, the horns attached mostly near the middle of the hoods, tangentially flat to subdigitate, 0.5-1.5 mm long, included to scarcely exserted; anther wings 1.1-1.7 mm long; corpusculum ca. 0.2-0.3 mm long, the pollinia 0.5-0.7 mm long Fruit: FOLLICLES erect on deflexed to spreading pedicels, 4-6 cm long Misc: widely scattered localities on the high deserts and dry plains REFERENCES: Sundell, Eric. 1994. Asclepiadaceae. J. Ariz. - Nev. Acad. Sci. Volume 27, 169-187.
Woodson 1954, Sundell 1993, Nabhan et al 2015
Duration: Perennial Nativity: Native Lifeform: Forb/Herb General: Small dwarf herbaceous perennial, stem ascending to decumbent, 1.5-4 cm long, inconspicuously puberulent. Leaves: Opposite to irregularly alternate, variable, the lowermost are ovate, then grading to linear-lanceolate above, 1-2 cm long, 2-7 mm across, minutely puberulent, with short woolly margins. Flowers: Umbel one to several, short pedunculate, the flowers small, calyx lobes ovate lanceolate about 2-4 mm long, the corolla reflexed rotate, purplish rose, lobes about 4 mm long, the hoods are shortly saccate and about 1.5 mm long, with acute marginal auricles. Fruits: Follicle erect on deflexed to spreading pedicel, 4-6 cm long. Ecology: Found in grasslands on sandy to rocky soil from 5000-7000 ft (1524-2134 m); flowers May-June. Distribution: Found in very localized habitats from the Great Plains to southeastern Arizona. Notes: This is a variable complex of species. Sundell 1993 separated them into two varieties, but only one of them is still considered a subspecies. Subsp. ruthiae was distinguished as having stems 10-20 cm long, blades mostly elliptic or circular. The flowers were large with corolla lobes 4-6 mm long and hoods with indistinct hoods. This taxa was also previously known as A. eastwoodiae and is known from from the Colorado Plateau from a number of collections identified to A. ruthiae. Known queen butterfly (Danaus gillipus) host plant. Etymology: Asclepias is named for the Greek god of healing Asklepios, while uncialis means one-twelfth or one inch in length. Synonyms: None Editor: SBuckley 2014 , AHazelton 2015
Asclepias uncialis image
Robert Sivinski  
Asclepias uncialis image
Frankie Coburn  
Asclepias uncialis image
Frankie Coburn  
Asclepias uncialis image
Asclepias uncialis image
Asclepias uncialis image
Asclepias uncialis image
Asclepias uncialis image