Asclepias hirtella (Pennell) Woodson
Family - Asclepiadaceae
Stems - To +1m tall, densely pubescent in upper 1/2, sparse pubescent to glabrous below, herbaceous, simple, erect to ascending, from a thick taproot, with milky sap, often reddish in strong sun.
Leaves - Alternate, short-petiolate,
dense on stem. Petiole to 7mm long, scabrous. Blade linear-lanceolate, entire,
to +13cm long, 1.5cm broad, scabrous on margins and midrib. Margins thickened
and often reddish.
Inflorescence - Axillary
umbellate cymes with +/-60 flowers. Peduncles dense pubescent. Pedicels
hispidulous, to +/-1.5cm long in flower. Cymes subtended by linear bracts
to 6mm long. Bracts pubescent.
Inflorescence.
Flowers - Petals 5, reflexed,
to 5mm long, 1.5mm broad, glabrous or very sparse pubescent, greenish white
and purplish at apex. Anther head 3mm long(tall), 2.2mm in diameter. Pollinia
1.4mm long. Hoods 2.1mm long, whitish with purple tinge at base, appressed
and attached to column for most of length. Carpels 2, 2.1mm long, glabrous.
Sepals 5, reflexed, ovate, 2.1mm long, 1.2mm broad, hispidulous externally,
glabrous internally, reddish at apex. Follicles fusiform, erect, to +12cm
long, +/-1cm in diameter, pubescent. Seeds to 9mm long. Coma whitish, to
+3cm long.
Flower close-up.
Flowering - May - August.
Habitat - Prairies, glades, and pastures.
Origin - Native to U.S.
Other info. - I placed this
species in the white flowers section of this site because from a distance
the entire inflorescence has a whitish appearance. Close up, however, the
flowers have a definite purplish-green tinge. This species is easy to ID in the
field because of its stout pubescent stems, many flowered inflorescences,
and linear lanceolate leaves (which are alternate). The plant is common
throughout most of the state except for apparently some areas of the Ozarks.
Photographs taken off Hwy 126, Barton County, MO., 7-4-03, and in Wayne Fitzgerrell State Park, IL., 8-3-05.
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