Penstemon pallidus Small - Pale Penstemon

Penstemon pallidus plant

Family - Scrophulariaceae

Stems - To +40cm tall, from small caudex and taproot, single to multiple from base, simple, densely glandular-villous below, dense glandular-pubescent above, herbaceous, greenish-red in strong sun.

Penstemon pallidus stem

Leaves - Basal leaves in rosette, spatulate, dentate to serrate, petiolate, to 5cm long. +1cm broad at apex. Cauline leaves opposite, to +10cm long, +1.5cm broad, linear to linear-lanceolate, acute, partially clasping, serrate-dentate, pubescent above, pubescent on midrib below.

Penstemon pallidus leavesTypical leaves.

Penstemon pallidus leavesMore toothed leaves.

Inflorescence - Terminal thryse to +20cm long(tall). Cymes in +/-4 verticillasters. Cymes with +8 flowers each. Peduncles and pedicels with dense glandular and non-glandular pubescence. Peduncles spreading to ascending. Each division of inflorescence subtended by pair of linear-attenuate bracts. Bracts much reduced, villous, green.

Penstemon pallidus inflorescence

Flowers - Corolla whitish with a pink tinge, to +2cm long, bilabiate, glandular pubescent externally (especially near base), constricted near base in calyx. Upper lip of corolla 2-lobed. Lobes rounded, 2-3mm long and broad. Lower lip of corolla 3-lobed. Lobes larger than those of upper lip, streaked with purple lines internally. Stamens 4, adnate at base of corolla tube. Filaments to 2cm long, glabrous. Anthers brown, 2mm long. Staminode adnate near apex of corolla tube, pubescent in upper half, (some hairs flattened, other hairs terete and bristle-like). Style 1, included, glabrous, filiform, 1.3cm long. Ovary green, glabrous, superior, 2.1mm long, ovoid-conic, 2-locular. Placentation axile. Calyx 5-lobed. Lobes glandular pubescent externally, 5mm long, 2mm broad, lanceolate, acute to acuminate, with slightly scarious margins. Capsule to 7mm long.

Penstemon pallidus calyxCalyx.

Penstemon pallidus flower

Flowering - April - July.

Habitat - Dry open rocky woods and glades, bluff ledges, prairies, railroads.

Origin - Native to U.S.

Other info. - This species is fairly common in Missouri. It occurs in dry harsh areas. Except for the leaves, nearly the entire plant is densely covered with gland-tipped hairs.
Many of the white flowered species of Penstemon look alike at first. Carefully check your plants for a proper ID.

Photographs taken in Eminence, MO., 5-23-03.


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