Senna marilandica (L.) Link

Southern Wild Senna

Senna marilandica plant

Family - Fabaceae

Stems - To +/-2m tall, multiple from caudex, glabrous, herbaceous, erect, with "zig-zag" growth pattern near apex.

Leaves - Alternate, petiolate, even-pinnate, to +20cm long, with +/-20 leaflets. Petiole with pair of glands at base. Glands cylindrical, 2.5mm long, 2mm in diameter, brown. Leaflets glabrous, oblong to narrowly ovate, to +5cm long, -2cm broad, mucronate. Margins of leaflets ciliate and yellowish in color. Petiolules to 2.5mm long, sparse pubescent.

Senna marilandica leaf Senna marilandica stipule
Leaf, stipules, and pulvinus

Inflorescence - Dense axillary racemes to 6cm long. Peduncle with black glands. Pedicels to 1.5cm long, with black glands, sparse pubescent.

Senna marilandica inflorescenceInflorescence

Senna marilandica flowersFlowers

Flowers - Petals 5, yellow, spreading, free, subequal, to 1.3cm long, 5mm broad, rounded at apex, glabrous, spatulate. Stamens 10, unequal. Upper 3 stamens much reduced. Lower 3 stamens to 1.2cm long. Filaments glabrous, yellow. Anthers brown, flattened to terete. Style green, 3mm long. Ovary 8mm long, densely pubescent in opposing vertical lines. Sepals 5, yellow, 5-6mm long, 3-4mm broad, acute, ciliate margined, glabrous, reflexed. Fruit a thin flat pod to +/-10 cm long, +/-1cm broad, black.

Senna marilandica flowerFlower close-up.

Senna marilandica fruit Senna marilandica fruitsFruits.

Flowering - July - August.

Habitat - Open rocky woods, thickets, wet meadows, bases of bluffs, slopes.

Origin - Native to U.S.

Other info. - This is a common plant in the state. It seems to prefer a moist soil location and bright sun.
Being a perennial and having a shrubby growth habit, it seems ideal for cultivation and frequently is planted for ornamental use.

Photographs taken in the Ozark Scenic Riverways, Shannon County, MO., 7-22-04 (DETenaglia), and at Shaw Nature Reserve, 8-9-2008, and near Dutzow, MO, 8-4-2013 (SRTurner).