Trifolium reflexum L. - Buffalo Clover

Family - Fabaceae

Stems - Multiple from a taproot, ascending, herbaceous, purple in strong sun, terete and sometimes carinate, pilose or glabrous, to +/-30cm tall, branching.

Leaves - Alternate, trifoliolate, stipulate, petiolate. Stipules to +2cm long, 1cm broad, ovate to lanceolate, acuminate, entire or with crenulate margins, pilose. Petioles pilose, to +10cm long. Leaflets sessile, pilose, equal, emarginate to rounded at the apex, with or without a minute mucro, obovate to rhombic or spatulate, with serrulate margins, to 4cm long. Upper leaves reduced.

Stipule.

Inflorescence - Terminal pedunculate globose umbel +/-50 flowers. Peduncle pilose or glabrous and carinate, to 10cm long. Pedicels 3-4mm long, pilose. Flowers erect to spreading at first but quickly reflexed.

Flowers - Corolla papilionaceous, white to greenish-white. Standard whitish-green, 8-10mm long, 4-5mm broad, glabrous. Wings and keels to 7-8mm long. Wings connate to the keels at about the middle. Stamens diadelphous. Stamen tube white, to 3mm long, glabrous. Free portion of the filaments to 3mm long and deflexed. Anthers yellow, to 1mm long. Ovary superior, green, 3mm long, mostly glabrous but with white floccose hairs at the apex, slightly compressed. Style 3mm long, greenish-white, glabrous, deflexed at the apex. Stigma small, capitate, yellowish. Corolla drying brown and persistent around the developing fruit. Calyx 5-lobed. Calyx tube to -2mm long, pilose or glabrous externally, glabrous internally. Lobes linear, subequal (4 equal and the lowest slightly smaller), acute, ciliate or glabrous, 4-5mm long. Fruit inflated, to 5mm long, on a stipe to 1.5mm long.

Flowers.

Infructescence.

Flowering - May - August.

Habitat - Rocky open woods, glades, old fields, prairies. Typically on acid soils.

Origin - Native to U.S.

Other info. - This species can be found throughout much of Missouri. The plant is fairly easy to identify in the field because of its big flower heads and reflexed fruits. There are two varieties of the species in Missouri. Variety reflexum (pictured above) has hairy stems and calices. Variety glabrum Lojacono has stems and calices which are glabrous. The two varieties may not be valid.

Photographs taken near Stegal Mountain, Shannon County, MO., 6-4-04.


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