Nuttallanthus texanus (Scheele) D.A. Sutton - Texas Toadflax

Nuttallanthus texanus plant

Family - Scrophulariaceae

Stems - To +/-50cm tall, prostrate to erect, herbaceous, from fibrous roots, glabrous, terete, single or multiple from base, typically simple or branching.

Nuttallanthus texanus stem

Leaves - Leaves of flowering stems alternate, linear, sessile, to +3.5cm long, +/-3mm broad, glabrous, entire, glandular punctate. Margins slightly thickened.

Inflorescence - Terminal compact raceme, elongating in fruit to +20cm long(tall). Axis sparse glandular pubescent to glabrous. Each flower subtended by a single bract. Bracts to 3mm long. Pedicels to 4mm long, glandular pubescent to glabrous.

Nuttallanthus texanus inflorescence

Flowers - Corolla blue-purple, with lighter palate, spurred, bilabiate, glabrous externally, pubescent(bearded) internally. Upper lip erect, 2-lobed, to 5-6mm long. Lower lip to 8mm long, 1.3cm broad, glabrous, 3-lobed. Spur to 10mm long. Stamens 4, didynamous. Stigma capitate. Ovary glabrous, 2-locular. Calyx 5-lobed, accrescent. Lobes to 3mm long, 1mm broad (in flower), linear-oblong, acute, green, glandular pubescent. Capsules to 3mm long and broad, many seeded, glabrous.

Nuttallanthus texanus calyx

Nuttallanthus texanus flower

Flowering - April - September.

Habitat - Open ground, glades, bluffs, prairies, roadsides, railroads.

Origin - Native to U.S.

Other info. - This attractive little species can be found in the southern half of Missouri. The plant can be identified by its irregular blue flowers which have a big basal spur. The spur of the corolla is filled with nectar to attract pollinating insects. The spur is longer than the calyx in this species and is typically 5-10mm long. Another species, N. canadensis (L.) D.A. Sutton, is similar but has smaller flowers with a spur 2-6mm long. This latter species is much less common in Missouri.

Photographs taken at Tuskeegee National Forest, AL., 3-26-05.


Back