Rhizomatous or stoloniferous marshland perennials. Leaves 1–4 x pinnately divided, ultimate segments medium-sized or minute. Umbels compound; bracts absent or few; bracteoles several linear. Calyx teeth small. Petals obovate, with an acute inflexed tip. Stylopodium conical, often hidden by calyx. Fruit ovoid-ellipsoid, glabrous, mericarps unequally ribbed, lateral pair of ribs broader and corky.
Key to species
Oenanthe hookeri C.B.Clarke
Stems fleshy, weakly erect to 100cm long. Leaves 4–20cm, simple or sparingly once pinnate; rachis grass-like, flattened 2–3mm broad; segments up to 3 pairs, linear, 2–25 x 0.5mm, glabrous. Umbels rather few, 3–4cm across, 6–9-rayed; rays 1.5–3cm; bracteoles 2–3mm; umbellules 0.75–1cm across. Calyx teeth c 1mm. Petals white sometimes tinged pink, obovate-spathulate, 1–1.25mm. Styles short c 1mm. Fruit narrowly ellipsoid c 2.5 x 1.5mm.
Bhutan: C—Ha district (Ha [Lit. Ref.117]), Thimphu district (Paro [Lit. Ref. 117], Sharna to Choidi Ponkey, Taba, Tashi Cho Dzong, Thimphu) and Bumthang district (Dhur Valley).
Ecology: Locally abundant in wet meadows and marshes, 2200–3000m. Flowers July–September.
Illustration [51 f-h]
Specimen List 
Oenanthe javanica (Blume) DC.
Bhutan: S—Deothang district
(Narfong [Lit. Ref.117]); C—Tongsa district (Tongsa) and Tashigang
Ecology:. Marshy ground, roadside ditches, 150–2600m. Flowers April–October.
Specimen List 
Oenanthe thomsonii C.B.Clarke
A weak diffuse herb with stems 20–80cm. Leaves 3–15(–30)cm long, finely 3–4 x pinnately divaricately divided, ultimate segments linear c 1.5 x 0.25mm. Umbels 3–5.5cm across, 3–9-rayed; peduncle 1–7cm; rays 1–2.5cm; bracteoles 2–3mm; umbellules 6–10mm across; pedicels 2–7mm. Calyx teeth 0.5–1mm. Petals white, 1.25–1.5mm long. Styles 0.75–1mm. Fruit ovoid 2.5–3 x 2mm.
Bhutan: S—Chukka district
(Gedu), C—Tongsa district (Chendebi) and Mongar district (Namning,
Ecology: A locally common plant of marshy ground in wet broad leaved forest, roadside ditches, etc., 1000–2500m. Flowers April–August.
Specimen List