Cream Cups Poppy. Platystemon californicus, Poppy Family ( Papaveraceae ), Cream Cups Poppy. We wish to thank Wikipedia, the free encyclopedia for some of the information on this page. We share images and information with Wikipedia. Platystemon californicus is the only single species of the genus Platystemon of the poppy family ( Papaveraceae ). Platystemon californicus is known by the common name Creamcups. It is found in open grasslands and sandy soils. It is also used as an ornamental plant for landscaping and revegetation of recently burned areas. Cream cups are low, soft-pilose, many-stemmed, dicot, herb, annuals. They are quite variable in appearance. Quick Notes: Height: Up To About 12 Inches Tall. Flowers: White. Flowers are solitary and terminal on long, almost leafless stems. Each flowering head has three hairy sepals and six white to cream-colored unfused petals, many stamens with flattened filaments, and a single pistil. Flowering Time: Mid March - May. Leaves: Opposite, entire, lance-linear leaves to 2" long that are mostly on the lower part of the plant. Found: Native to the USA (AZ, CA, DC, OR, UT); and northern Sonora, Baja Norte, & Baja California, in Mexico. Hardiness: USDA Zone 9b: to -3.8 �C (25 �F) USDA Zone 10a: to -1.1 �C (30 �F) USDA Zone 10b: to 1.7 �C (35 �F) USDA Zone 11: above 4.5 �C (40 �F) Soil pH requirements: 5.6 to 6.0 (acidic) 6.1 to 6.5 (mildly acidic) 6.6 to 7.5 (neutral) 7.6 to 7.8 (mildly alkaline) 7.9 to 8.5 (alkaline) Sun Exposure: Full Sun Elevation: 800 - 3,000 Feet. Habitat: Found in open grassy clay or sandy places in valley grassland, chaparral and oak woodland. Miscellaneous: Flowering Photos Taken May 1, 2003. Near Lake Pleasant, Arizona. Other Plant Photos. Bartlett Lake, Arizona. March 09, 2009.