Diodia virginiana L.
Family - Rubiaceae
Stems - Trailing to ascending, herbaceous, 4-angled, often with reddish tinge, retrorse pubescent to glabrous, to +15cm tall, +30cm long.
Leaves - Opposite, sessile.
Pairs of opposing leaves joined at base by sheathing stipules. Stipules
with 3-5 bristle-like lobes on upper margin. Middle lobe longest, to 5mm
long. Leaf blades to 4cm long, 1.5cm broad, elliptic below, becoming linear-oblong
above, entire, with antrorse strigillose margins, glabrous or sparse pilose
at base on margins, typically acute.
Inflorescence - Single or double flowers from leaf axils. Flowers sessile.
Flowers - Corolla white,
4-lobed, salverform. Corolla tube to 8mm long, glabrous. Lobes 5-6mm long,
2.5mm broad spreading, white, glabrous externally, dense pubescent internally.
Stamens 4, alternating with corolla lobes, adnate at apex of corolla tube, exserted.
Filaments to +4mm long, white, glabrous. Anthers 2mm long, white. Style 1.1cm
long, glabrous, filiform, flattened. Stigmas 2, 4mm long. Ovary 2-locular.
Calyx tube to 4mm long (in flower), 2-lobed. Lobes 6mm long, attenuate,
ciliate-margined. Caylx accrescent. Fruit to 8mm long, pubescent to glabrous.
Corolla tube.
Flowering - June - September.
Habitat - Wet soils, pond margins, wet meadows.
Origin - Native to U.S.
Other info. - This species
can be found in the lower 1/3 of Missouri. Our plants belong to variety
virginiana. Another variety, var. attenuata
Fern., has more narrow fruits and is not found in Missouri.
Steyermark splits var. virginiana
into two forms. Form hirsuta (Pursh) Fern. has pubescent stems and fruits. Form virginiana has glabrous stems and fruits and is more common in our state.
Photographs taken in the Croatan National Forest, NC., 7-11-02.
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