Tom Van Devender, Donald Pinkava & Jon Rebman
United States, ARIZONA, Pima County, T17S R14E NW3 SE3 S28, .8mi NW of the boundary of the Santa Rita Experimental range and wildlife Area, along Santa Rita Road, 3.5 air miles SE of Sahuarita, mesquite thicket along drainage
pale brown silt of flat with Ambrosia confertiflora, Atriplex canescens, Brickellia coulteri, Carnegiea gigantea, Celtis pallida, Cylindropuntia arbuscula, C. fulgida, C. leptocaulis, C. spinosior, Eragrostis lehmanniana, Ferocactus wislizeni, Isocoma tenuisecta, Opuntia engelmannii, O. macrocentra, Parkinsonia florida, Prosopis velutina, and Zinnia acerosa.
Open shrub 2.5m tall, 3m broad, from 2 trunks 4cm dia; older bark dark gray, fissured; 2º branches twisting-ascending, unbranched below; main upper stems with ca. whorled branching; ultimate stem segments to 2dm long, the shorter very easily detached; fruit generally tuberculate, oblong, truncate, ca. tapered toward base, single or in chains of two, often with a few caducous spines, same color as stem or tinged orange, especially above & toward apex; umbilicus to 1cm deep; three individuals in area, smaller individual with habit similar to C. spinosior; this is probably a clone of 10476; flowers buds collected during meiosis of microgametogenesis 19 May 2009 from individual transplanted to outside garden (south side of building in partial shade), Chino Valley, Arizona; flowers (2) collected and pressed 2 June 2009; n=55/2 during meiosis of microgametogenesis; fruits photographed 4 November 2009.