Trachyspermum ammi Sprague

Annual herb, ± 25–65 cm. tall, much branched from near the base upwards except in depauperate plants, with long divergent or more divaricate branches; stem and branches glabrous, slender, striate and terete or the stem somewhat sulcate.. Basal leaves withered at time of flowering; lowest stem leaves ± 5–14 × 2–6 cm., lamina broadly oblong or ovate, ± bi-or subtripinnate with 3–5 pairs of pinnae, basal pair sessile or with petiolules up to ± 5 mm.; pinnae rather irregularly divided into narrowly linear, glabrous, rather bluntly mucronate segments up to ± 1.4 cm. long and ± 0.5 mm. wide, with ± revolute margins and not dentate; petioles ± 2.5–8 cm. including the tapering, 8–12 mm., ribbed sheath; upper stem leaves reduced and more shortly petiolate and finally sessile but similar; uppermost leaves also much divided, but small.. Umbels numerous, with 6–20 usually obviously unequal rays 5–21 mm. long, glabrous to minutely scabrid; involucre conspicuous, of 2–4 linear or sometimes trisect or ± pinnate, scabrid-margined, often unequal bracts 3–20 mm. long; partial umbels ± 8–24-flowered, pedicels 1–4 mm., minutely scabrid to subglabrous; involucel of ± 6–8 subulate bracteoles 1–5 mm. long, with scabrid margins; peduncles ± 2–8.5 cm., glabrous.. Calyx with very short but distinct, broadly triangular, pale teeth.. Petals white or tinged with pink, obcordate with broad lobes, 1–1.25 mm., shortly white-hairy; anthers dark purplish black.. Fruit ovate, ± 2–2.5 × 1.75–2 mm., covered with white papillae or at the extreme apex frequently glabrous or almost so and deeply grooved, ribs prominent; stylopodia bluntly conical; styles slender, deflexed or flexuose, subequalling to twice as long as the stylopodia.. Fig. 14/8.

It is a temperate to tropical plant. In Nepal plants grow to 1500 m altitude.

The fruit yield oil and are used as a spice. It has a thyme-like flavour. It is used in curries, bean dishes and biscuits. The seed is tiny and pungent. It looks like celery seed but the flavour is like thyme. The seeds are used in lentil dishes, bread and pickles.

Plants are grown from seed. The seeds are ready to harvest when the flower heads turn brown. The plants are pulled up and dried in the sun. They are then rubbed to separate the seeds.