Plant: Rhizomatous perennial forb, much-branched, to 60 cm Leaves: leaves absent, branches green, often spiny Flowers: flower heads 5-7 mm high, ray flowers white, disk flowers yellow; pappus of capillary bristles. Notes: Upper leaves scale-like.Number of ray flowers per head are 15-30. References: Kearney & Peebles; Arizona Flora. McDougall; Seed plants of Northern Arizona. ASU specimans