Matelea baldwyniana (Sweet) Woodson


Matelea baldwyiana plant

Family - Asclepiadaceae

Stems - Twining, climbing, herbaceous, brownish, with milky sap, hirsute and with glandular pubescence (some hairs with swollen glandular bases), from thickened roots.

Matelea baldwyiana stem

Leaves - Opposite, petiolate. Petiole 5-6cm long, with same pubescence as stem. Blade to +/-13cm long. +/-10cm broad, broadly ovate to orbicular, cordate, entire, acute to acuminate, scabrous above from swollen pubescence, appearing punctate because of swollen hairs.

Matelea baldwyiana plant

Inflorescence - Axillary umbellate cymes with +15 flowers. Peduncles to 6cm long. Pedicels to +2cm long. Peduncles and pedicels with same pubescence as stem.

Flowers - Corolla white, 5-lobed. Lobes twisting, +/-1.2cm long, 2-3mm broad, with same pubescence as stem externally, glabrous internally, blunt to slightly emarginate. Corona 5-lobed. Lobes to .5mm long, alternating with appendages. Appendages to .8mm long, often bifurcate. Pollinia minute, +/-.1mm broad, .3mm long, with dark reddish-brown translator. Anther head discoid, +/-1.3mm broad (diameter). Calyx 5-lobed. Lobes 3-4mm long, lanceolate, spreading to slightly recurved, densely brown glandular. Follicles to 9cm long, tuberculate. Seeds ovate, to 9mm long. Coma to +3cm long, tan.

Matelea baldwyiana flower

Matelea baldwyiana calyx

Flowering - May - June.

Habitat - Moist ground of rocky open woods and thickets. Also on glades.

Origin - Native to U.S.

Other info. - This is one of 4 species of the genus found in Missouri. This plant prefers moist ground and is found mostly in the southwest corner of the state.
This is an easy species to identify becasue of its opposite leaves, pubescent stems, and white flowers. The flowers have twisted petals.

Photographs taken at Busiek State Forest, MO., 6-17-05.