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Cochlospermaceae
Amoreuxia gonzalezii is a herbaceous perennial with a thick, starchy root. Leaves are long petioled, palmately 5-7 lobed, 2.5-5.5 cm long. Flowers are few on a single stem, bilaterally symmetric with five petals, 6-8 cm wide, and orange in color. The anthers are showy, with lower anthers cream-colored, and upper anthers a light cerise. Fruits are elliptical, pendulous, with round seeds. The anthers and the shape of the fruits and seeds separate it from A. palmatifida, which has all purple anthers, and rounded fruits with kidney-shaped seeds.
Two species of Amoreuxia are found in Arizona and Sonora. Amoreuxia palmatifida, the more common species extends from Arizona far south into central America, while the distribution of the very rare A. gonzalezii is not known. Few herbarium specimens of the species have been made. The fleshy roots of both species were eaten by the Seri, Pima and Tohono O'odam people living in the area. A. gonzalezii appears to be an extremely rare plant, known only from two localities in the Santa Catalina Mountains in southern Arizona. In Sonora, it is known to occur in seven to nine localities. The species was listed as a Category 2 taxon under the Endangered Species Act, and has now lost its protection through a 1996 revision amending Category 2 plants to 'species of concern'. Threats to plants besides its limited occurrence include development, grazing, mining, habitat degredation, competition with introduced exotic grasses and rarity.
Little is known about the reproductive biology of A. gonzalezii. There is some speculation that pollen dehiscence is triggered by the buzzing vibrations of native bees, but this remains unconfirmed. Desert Botanical Garden has 5 plants from seed, 142 seeds collected in Arizona and 72 seeds collected in Mexico. Garden staff has produced seed in cultivation by rubbing flowers together. Repeat visits to the population in the Santa Catalina Mountains confirm the low reproductivity of plants in the U.S. Removal of seeds from habitat must carefully be considered on an annual basis. No seeds should be collected in most cases. In the future, surveys for additional populations in the U.S. and Mexico are needed.
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