Robinia hispida L. - Bristly Locust

Robinia hispida plant

Family - Fabaceae

Stems - To +3m tall, woody, typically multiple but sometimes simple. All but the oldest wood densely hispid. New growth glandular-hispid.

Robinia hispida twigNew seasons' twig.

Leaves - Alternate, odd-pinnate, to +30cm long. Leaflets opposite (sometimes subopposite), glabrous, ovate to oblong, entire, very short-petiolate, mucronate.

Inflorescence - Drooping axillary racemes of +/-10 flowers, to +10cm long. Peduncles and pedicels hispid.

Flowers - Corolla light pink to rose, papilionaceous, to 2.5cm long. Standard to +2cm broad, 1.7cm tall, with yellow spot in center. Stamens diadelphous, tube to 1.4cm long. Anthers yellow-orange, .7mm long. Ovary tuberculate, becoming hispid in fruit, to 1.3cm long. Style upcurved, 6mm long. Stigma elongated, 3-4mm long. Calyx campanulate, bilabiate, hispid. Upper lip with two lobes. Lobes to 3.5mm long, attenuate. Lower lip 3-lobed. Lobes attenuate, to 5mm long. Fruits densely hispid, to +/-8cm long.

Robinia hispida calyxCalyx.

Robinia hispida flower

Robinia hispida fruitsFruits.

Fruit -

Flowering - May - June.

Habitat - Cultivated and rarely escaped to open woods, slopes, and open thickets.

Origin - Native to the southern U.S.

Other info. - This is a very striking plant not only for the flowers but also for the fruits and twigs. The plant is fairly common in cultivation. It can be identified by its pinkish flowers, bristly twigs, and shrubby habit.

Photographs taken near Birmingham, AL., 5-10-04.


Back