About Arivela viscosa (L.) Raf.
Arivela viscosa (L.) Raf. plants grow to a height of (10โ)30โ100(โ160) cm, with viscid stems. Leaves have glandular-hirsute petioles that measure 1.5โ4.5(โ8) cm. Leaflet blades are shaped ovate to oblanceolate-elliptic, sized (0.6โ)2โ6 cm by 0.5โ3.5 cm, with entire, glandular-ciliate margins and acute to obtuse apices; both leaf surfaces are glandular-hirsute. Racemes are 5โ10 cm long, growing to 10โ15 cm when bearing fruit. Bracts are trifoliate, 10โ25 mm, glandular-hirsute, and often deciduous. Pedicels are 6โ30 mm long and glandular-hirsute. Flowers have green, lanceolate, glandular-hirsute sepals measuring 5โ10 mm by 0.8โ1.2 mm. Petals are arranged in an adaxial semicircle before anthesis, and radially arranged at anthesis; they are bright yellow, sometimes with purple coloring at the base, and shaped oblong to ovate, measuring 7โ14 mm by 3โ4 mm. Stamens are dimorphic: 4โ10 adaxial stamens are much shorter, with a swelling proximal to the anthers, green, and 5โ9 mm long. Anthers are 1.4โ3 mm long. The ovary is 6โ10 mm long and densely glandular; the style is 1โ1.2 mm long. Capsules dehisce only partway from the apex to the base, measure 30โ100 mm by 2โ4 mm, and are glandular-hirsute. Seeds are light brown, measure 1.2โ1.8 mm by 1โ1.2 mm, and have fine transverse ridges. The chromosome count is 2n = 20. This species flowers from June to August, during the summer.
