square kilometers (almost 20,000 acres) of former agave fields have been discovered mostly between Phoenix and Tucson indicating that the agave was a major source of food for the Hohokam who numbered in the tens of thousands. Undoubtedly many other fields have been destroyed or are undetected by archaeologists. Agave was cultivated by the Hohokam in the desert of the Tucson basin in rocky areas above the floodplain of the Santa Cruz river where more water-dependent crops were grown. The Hohokam planted agave in rockpiles about across and high. The pile of rocks around the base of the agave plant act as a mulch to help preserve moisture and prevent rodent predation. Check dams and contour terraces help channel the runoff from precipitation to the agave plants. About one-tenth of the Hohokam agave plants flowered each year and were harvested. The fields are dotted with the remains of large roasting pits for the agave. Rockpile cultivation began about 600 AD. Large-scale production characterized the classic period of Hohokam culture from 1150 to 1450. In one representative area, Marana, cultivation totalled . The production of agave in Marana is estimated to have been sufficient to provide 20% of the daily caloric needs of 775 people and the daily protein needs of 550 people. Moreover, because of its hardiness and low demand for moisture the agave was probably a very reliable crop in the drought-prone desert. Hohokam agave was apparently bred for human consumption by Native Americans over many generations. It has several advantages as a plant and food source over other agaves. The acidic juice in its leaves is less caustic than that of many agave species; the Hohokam agave is ready for consumption in late winter and early spring when other agricultural crops are not productive. Botanics Plants acaulescent, freely suckering; rosettes cespitose, 6–12 × 8–14 dm, open. Leaves ascending, 50–80 × 6–10 cm; blade light glaucous green to yellow green, frequently lightly cross-zoned, spatulate, firm, adaxially concave toward apex, abaxially convex toward base; margins undulate, armed, teeth single, well defined, mostly 3–4 mm, ca. 1–2 cm apart; apical spine dark brown to grayish, conical, 1.2–2 cm. Scape 3–4 m. Inflorescences narrowly paniculate, prolifically bulbiferous; bracts persistent, triangular, 10–15 cm; lateral branches 10–16, slightly ascending, comprising distal 1/4 of inflorescence, longer than 10 cm. Flowers 12–21 per cluster, erect, (5.1–)6–7.5 cm; perianth cream, apex purplish or brownish, tube urceolate, 14–20