About Penstemon watsonii A.Gray
Penstemon watsonii is a herbaceous penstemon species that grows 25 to 65 centimeters tall. Its stems are slightly hairy or occasionally smooth, and may grow outward a short distance before curving upward, or grow straight upward from the plant base. Stems emerge from a frequently branching caudex, and this species is relatively long-lived among penstemons. Basal leaves, which grow from the base of the plant, are either absent or poorly developed. Cauline leaves, which attach to stems, grow in opposite pairs, with four to eight pairs per stem. These leaves have very short petioles (leaf stalks), or their bases attach directly to the main stem; higher on the stem, leaf bases clasp the stem. Leaves are typically 30 to 70 millimeters long, ranging from 13 to 80 millimeters in total length, and 8 to 35 millimeters wide. Their shape ranges from oblanceolate (inverted spear-head shape) to lanceolate (spear-head shape, wider toward the base rather than the tip). The inflorescence holds flowers arranged from somewhat dense to grouped in clusters, with each cluster attached at two points on opposite sides of the stem. Each cluster usually holds three to seven flowers, and occasionally as many as ten. The funnel-shaped flowers are 12 to 18 millimeters long, and range in color from blue to purple or violet, with red-purple nectar guides. Flowers are smooth on the outside, and have sparse white hairs inside the floral tube. The staminode is 8 to 9 millimeters long, reaches the flower opening but does not extend past it, and is covered in 1 millimeter long golden yellow hairs. Penstemon watsonii is native to the central Intermountain West of the United States, where it grows in western Colorado, most of Utah, much of eastern Nevada, and parts of southern Idaho. It is only known to occur in Mohave County, Arizona, and was only recorded from Uinta County in far southwestern Wyoming, where NatureServe lists it as probably locally extinct. This species grows in gravelly or rocky soils at elevations between 1700 and 3200 meters, and is associated with sagebrush steppe, pine-oak woodlands, and open pine woodlands.
