[Beardtongues and Penstemons: The Genus Penstemon West of the Cascade Mountains of Oregon and Washington]

This photo shows the inflorescence of Siskiyou penstemon as seen along Coyote Creek Road in the Umpqua National Forest........June 25, 2005. The inflorescence consists of 2-7 verticillasters.

This photo shows a close-up of the stamens of Siskiyou penstemon as seen along Coyote Creek Road in the Umpqua National Forest........June 25, 2005.

This photo shows a view down onto the top of the inflorescence of Rattan's penstemon as seen along Coyote Creek Road in the Umpqua National Forest.........June 25, 2005. Note the numerous gland-tipped hairs on the sepals and outer corolla and the corolla tube which abruptly expands outwards at a point just beyond the sepals.

This photo shows the paired upper stem leaves of Siskiyou penstemon as seen along Coyote Creek Road in the Umpqua National Forest........June 25, 2005. Note that the upper stem leaves are clasping and sharply toothed.

Close-up images of Siskiyou penstemon as seen at the trailhead for Babyfoot Lake in the Siskiyous of southwestern Oregon............July 15, 2012.

Siskiyou penstemon as seen along the trail between Onion Camp and Whetstone Butte, Siskiyou National Forest..........July 15, 2012.