Duration: Perennial

Nativity: Native

Lifeform: Forb/Herb

General: Decumbent to ascending perennial with closely and minutely tomentose stems to 20 cm long, lower parts soon glabrate.

Leaves: Ovate to ovate-lanceolate, 2-9 mm long, oblique basally, entire, closely and finely tomentose on both surfaces; on petioles 1-2 mm long, with stipules 1 mm long, ventral ones usually connate, dorsal ones distinct.

Flowers: Solitary cyathia on very short peduncles, campanulate involucres, 1.2-1.5 mm in diameter, appressed-stiff hairs without and just below glands within, lobes narrowly deltoid, equaling glands, hairy; glands reddish, oblong; appendages usually twice as wide as glands, white, entire to crenate-margined, or appendages sometimes lacking; u-shaped sinus, densely hairy; 3-4 staminate flowers in each fascicle, 15-20 in a cyathium.

Fruits: Short tomentose, ovoid and lobed capsule, 1.5-1.7 mm long.

Ecology: Found on dry, rocky slopes or flats, and along washes from 500-5,000 ft (152-1524 m); flowers throughout the year.

Notes: These plants are generally erect or ascending, but on open flats, particularly in disturbed soil they are nearly prostrate.

Ethnobotany: Used for bee stings, sores, and earaches.

Etymology: Euphorbia is named for Euphorbus, Greek physician of Juba II, King of Mauretania, while melanadenia is of uncertain origin.

Synonyms: Euphorbia melanadenia

Editor: SBuckley, 2010

Plant: Perennial; stem decumbent to ascending, tomentose or becoming glabrous

Leaves: cauline, opposite, short-petioled, 2-9 mm; stipules separate, linear; blade ovate, tomentose, tip acute, margin entire

INFLORESCENCE: flower-like, generally 1 per node; involucre 1-1.5 mm, bell-shaped, tomentose; gland < 1 mm, oblong; appendage width = gland width, scalloped, white

Flowers: Staminate flowers 15-20, generally in 5 clusters around pistillate flower, each flower a stame; Pistillate flower: 1, central, stalked; ovary chambers 3, ovule 1 per chamber, styles 3, style divided > 1/2 length

Fruit: capsule, 1.5-2 mm, ovoid, lobed, tomentose; Seed 1-1.5 mm, ovoid, slightly wrinkled, white

Misc: Dry, stony slopes or flats; < 1300 m.; Dec-May

Notes: Flowers borne in a cyanthia, with 4 white petaloid appendages each with a dark purple gland.Stems sometimes reddish. Leaves turning reddish with age.

References: Kearney & Peebles; Arizona Flora. McDougall; Seed plants of Northern Arizona. ASU specimans