Sunflower oil is obtained by cold pressing first from the seed of the botanical species Helianthus annuus L. belonging to the Asteraceae family.

It is an annual plant that can be three meters high. The stems are generally erect and hispid. Most of the leaves are caulinar, alternate, petiolate, with a cordate base and serrated edges. The lower surface is usually more or less hispid, sometimes glandular and the upper surface glabrous. The involvement is hemispherical or wide and measures 15-40 mm and up to more than 20 cm. Involuble bracts called filariae are found in number of 20-30, and up to more than 100, oval to lanceolate —brutally narrowed at the apex— longitudinally veined, with the edge generally hispid or hirsute, like their outer faces, they are rarely glabrous. Receptacle with tridentate centimeter scales, with the largest median tooth and the hirsute tip. The ligules, 15-30 in number, and up to 100, from yellow to orange to red, measure 2.5-5 cm; florets, 150 to 1000, of the same color with reddish-brown stamens. The fruits are oval achenes, somewhat truncated at the base, 3-15 mm long, glabrous or almost, striated by very fine vertical grooves, dark in color, generally almost black – although they can also be whitish, reddish, honey-colored or well mottled or with lighter longitudinal bands. The vilano consists of two lanceolate scales of 2-3.5 mm accompanied, or not, by up to four obtuse scales of 0.5-1 mm, all early decayed (as indicated by its specific Latin name: annuus).