About Penstemon centranthifolius (Benth.) Benth.
Penstemon centranthifolius is a mature herbaceous plant that grows 30 to 120 centimeters tall. Its hairless stems are either erect, growing straight upward, or ascending, growing outward slightly before curving upward. Its leaves are cauline, meaning they attach to the stems rather than the plant base, and grow in 5 to 11 pairs arranged opposite each other on the stems. The leaves are thick with smooth edges; the longest leaves occur midway up the stems. Leaves measure 4 to 10 centimeters long and 1 to 4 centimeters wide, and range in shape from ovate (egg-shaped, wider toward the base) to lanceolate (resembling a spear head). Leaves can attach directly to the stem or via a short petiole. The base of each leaf may be tapered, or it may be auriculate-clasping, wrapping partway around the stem with ear-shaped projections. A long inflorescence occupies the top of the stem, holding narrow tubular flowers that are 2.5 to 3.3 centimeters long. The inflorescence usually makes up 15 to 60 centimeters of the stem, though it can occasionally reach up to 100 centimeters in length. The flowers are hairless, with two lips bearing projecting round to egg-shaped lobes, and are colored bright red to orange-red. Like the rest of the flower, the hairless staminode extends out of the flower opening, and measures 13 to 14 millimeters long overall. This species flowers from February to as late as July. Penstemon centranthifolius is native to California in the United States and Baja California in Mexico. In California, it grows as far north as Glenn County, and can be found in the California Coast Ranges, Sacramento Valley, San Joaquin Valley, Sierra Nevada foothills, Mojave Desert, Transverse Ranges, San Jacinto Mountains, South Coast, and Channel Islands. In Baja California, it grows mostly below 1,000 meters (3,300 ft), from the Sierra de Juárez south to the Sierra de San Borja. It grows in dry habitats, including open chaparral, California oak woodlands, Joshua tree woodlands, pinyon–juniper woodlands, pine forests, and coastal sage scrub. In Baja California, it also grows on mountain-adjacent alluvial fans called bajadas, in canyons, and on granitic hillsides.
