Castilleja sessiliflora aka Downy Paintbrush

Castilleja sessiliflora is a small plant called downy paintedcup. It is a perennial, so it lives for years. It belongs to Orobanchaceae, the broomrape family. Its home range runs from central Canada through western and central America. It reaches south into Mexico, as far as Jalisco. This plant grows in mild climates, in open, dry land. It grows on prairies, sandy plains, and rocky slopes. It also grows on shortgrass steppe, land with short grasses.

Plants form loose mats or small, low clumps. They stand about 0.3–1.3 feet (0.1–0.4 metres) tall. They spread about 0.7–1 foot (0.2–0.3 metres). A second estimate gives a height of 1 foot (0.3 metres). It gives a spread of 0.7 feet (0.2 metres). Plants grow at a medium rate, but clumps spread slowly. Fine, soft hairs coat the leaves. Pale bracts may have yellow, pink, or green tones. These soft shades mark this paintbrush of the open plains.

Flowers bloom from April to July. The timing depends on how far north they grow and available moisture. Bees and hawk moths come to drink nectar. Hummingbirds visit too, but visit paintbrushes with red bracts more often. The blooms feed insects that live in open grasslands. This role helps make the plant useful for restoring native grassland. Its low shape also suits plantings based on its prairie home.

Grow it in full sun and lean soil that drains well. Sand and loam suit it. Soil can be slightly acid, neutral, or slightly alkaline. It copes with drought and grows in dry or moist soil. Too much water can cause root rot. Strong competition from other plants can weaken it. Reports place its hardiness in USDA zones 3–8. This hemiparasite needs a host plant to grow well. Native grasses, such as blue grama, can act as hosts. Another suggested host is needle-and-thread. It is hard to grow outside plantings that restore grassland with suitable hosts. Seeds need cold stratification, a cold treatment. They must take root near host roots.

Only the corollas serve as food; they may taste slightly sweet. Small plants bear few flowers, so harvests yield little food. The bracts have little food value. This plant can take up selenium, so use caution. The source limits food use to small amounts of corollas. It lists no known uses as medicine. It also reports no risk of becoming a weed.