Flowers of Penstemon secundiflorus
are crowded onto one side of the stem. Leaves are thick and smooth. Stamens do
not stick out beyond the petals. Penstemons have a staminode, or non-functional
stamen. The staminode of P. secundiflorus is densely covered with golden
hairs.
Compare to Penstemon unilateralis.
Both species have flowers on one side of the stem. P. unilateralis, however,
has no hairs on the staminode and has narrower, greener leaves.