26 May 2026

This month tall stands of white flowers are blooming in many Pittsburgh gardens including Schenley Plaza and at Phipps Conservatory. Chosen for its beauty, foxglove beardtongue (Penstemon digitalis) has a weird name and an important characteristic: Deer don’t eat it.

Originally native to the Mississippi River basin it’s been planted widely in eastern North America. According to Wikipedia it is now the most widespread species of Penstemon east of the Mississippi River.

Its weird common and scientific names repeat each other.

• The flower resembles a Foxglove in the Digitalis genus.
• It has four active stamens (black tips in this photo) and a fifth false stamen (Penstemon) that has hairs on it (beardtongue).

The genus name Penstemon … may also come from the Greek penta meaning “five” and stemon meaning “stamen”. Both refer to the fifth, sterile stamen (staminode) that characterizes members of this genus. …

Penstemons are sometimes commonly called beardtongues because the sterile stamen (staminode) can be hairy.

— Missouri Botanical Garden Plant Finder: Penstemon digitalis

Looking closely at the outside of the flower I noticed tiny hairs that look sticky, like the hairs on sundew. Sundew hairs are for trapping insects. I believe these hairs are merely repelling them.

The flower stalk, calyx and exterior of the flower are all covered in short, dense, sticky glandular hairs.

… The scentless flowers, which may have a pink blush or fine violet nectar guides inside the corolla, are attractive to bees and butterflies, and may be visited by hummingbirds.

— Wisconsin Horticulture: ‘Husker Red‘ Foxglove Beardtongue, Penstemon digitalis

Foxglove beardtongue blooms in Pittsburgh in May and June. You still have more than a month to examine the flowers.