Fendler’s Penstemon — May 2010

Penstemon Plants

Fendler’s Penstemon

Penstemon Flowers

This month many open areas of the Preserve are decorated with erect stalks sporting regularly-spaced tubular flowers that are somewhat reminiscent of miniature lavender signposts pointing in all directions; like dry gulch - 22 miles, or big cat butte – 7 miles (if you dare). This sturdy perennial wildflower is Fendler’s penstemon, also known as Fendler’s beardtongue, with the comparatively easy to remember scientific name Penstemon fendleri. Penstemon comes from two Greek words, pente meaning five, and stemon the name of the male flower part we call a stamen. So this genus name means having five stamens and one of those five stamens in a penstemon flower is sterile and looks different than the other four pollen- producing stamens. Called a staminoid, this oddball has a hairy tip and is located at the throat of the floral tube, hence the other common name for flowers in this genus, beardtongue. The specific epithet is for Augustus Fendler, the same prolific German plant collector introduced in our March 2009 essay (Fendler’s bladderpod).

Fendler’s penstemon is easily recognized even when it’s not flowering by its triangular, thick, waxy, almost succulent gray-green leaves. The larger basal leaves have short petioles and smooth edges. The leaves along the stem arise in a paired, opposite pattern and lack petioles, sometimes with the leaf bases clasping the stem. All the leaves appear somewhat folded upward and their size diminishes up the stem until the leaves subtending the whorls of one to three flowers are small bracts. Fendler’s penstemon plants typically have one or very few stalks that can grow up to two feet tall. It is not unusual to find over half the length of these slender, erect stems bearing flowers.

The flowers of Fendler’s penstemon begin opening in late April and continue well into June. Their color may range from violet to blue, most commonly soft lavender. Individual flowers consist of five outer sepals fused into a cup with five lobes, and five petals fused into a narrow tube up to one inch long. The five lobes at the end of the floral tube are organized into two lips that are bent backwards. The upper lip has two lobes and the lower lip has three lobes. Purple lines decorate the inside the floral tube and the hairless anthers at the tips of the four fertile stamens do not protrude from the tube. Also visible inside the floral tube is the single staminoid with its hairy yellow tip. The fruit of Fendler’s penstemon develops as a dry olive-shaped capsule containing many seeds.

The genus Penstemon is unusually large with about 275 species all of which are endemic to North America. The 42 native species in New Mexico make Penstemon the third largest genus in our state in terms of number of species. To date, I have identified six species on the Preserve. The genus has traditionally been classified in the figwort family (Scrophulariaceae), however recent DNA evidence has necessitated moving this genus into the family Plantaginaceae. Of course you will still find penstemons listed in the family Scrophulariaceae in all but the very latest reference books. The only traditional use of Penstemon fendleri by Native Americans that I turned up was for the treatment of arrow or gunshot wounds by Navajos. Nonetheless Fendler’s penstemon and other penstemon species will continue to stand out as boldly colorful signal plants of our Southwestern American flora.

© 2010 Jerry Melaragno

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