Croton tinctorius L.
An erect-ascending annual herb up to 75 cm, sparingly, evenly or densely stellate-pubescent. Petioles 2-10 cm long. Leaf-blades broadly ovate-rhombic to ovate-lanceolate, (2-) 3-7 x (1-) 2-6 cm, obtuse, subacute or acute at the apex, cuneate or rounded or rarely subtruncate at the base, subentire to repand-dentate, 3 (-5)-nerved from the base, basal glands fairly prominent, sparingly, evenly or densely pubescent above and beneath. Stipules filiform, 1-3 mm long. Inflorescences 1-4 cm long, often produced above a stem di- or trichotomy. Male flowers subsessile; sepals lanceolate, 3-4 mm long, stellate-pubescent; petals elliptic-lanceolate, 4 mm long, lepidote without, yellowish-green; disc thick, c. 1 mm diam.; stamens (3-) 4-10 (-12), the filaments variously united into a column 3.5 mm high, anthers biseriate, 1.5 mm long. Female flowers: pedicels 5 mm long, extending to 3 cm in fruit and becoming deflexed, often upto 4 on a short peduncle; sepals and petals narrowly linear, otherwise as the ♂ sepals; ovary 2 mm diam., densely silvery-lepidote; styles stellate-pubescent and papillose, deeply bipartite, 2-3 mm long. Fruit rounded-trilobate, 5-6 x 8-9 mm, often somewhat tuberculate, stellate-lepidote, tinged with reddish-purple. Seeds triangular-ovoid, 4-5 x 3-4 mm, tuberculate, grey.
Fl. Per.: Jan: Sept.; Fr. Per.: Apr: Sept.
Holotype: France, Montpellier, Loefling s.n., Herb. LINN., 1140/5! (LINN).
Distribution: From Spain and N.W. Africa eastwards to Arabia and N.W. India. A common weed of fallow fields and dry waste places on sandy clay loam; 900 - 7500'/275 - 2300 m.
There is perhaps a case for keeping oblique separate from tinctoria further west, but in the east of their range they merge together.