Bunium bulbocastanum is a plant species in the family Apiaceae. It is related to cumin (Cuminum cyminum) and commonly called black cuminTemplate:Citation needed, blackseed,Template:Citation needed, black caraway,Template:Citation needed or great pignut,<ref name=BSBI07>Template:Cite web</ref> and has a smoky, earthy taste. It is often confused with Nigella sativa (which is also called black cumin,<ref name=GRIN>Template:GRIN</ref> blackseed,Template:Citation needed and black caraway<ref name=GRIN/>).
Dried B. bulbocastanum fruits are used as a culinary spice in northern India, Pakistan, Bangladesh, Afghanistan, Tajikistan, and Iran. It is practically unknown outside these areas. The tuber-like root is locally collected for food; the "pignut" or chestnut" names refer to it.Template:Citation needed
Local names for that spice are (काला ज़ीरा) kala zeera (black cumin) or shahi zeera (शाहि ज़ीरा)(imperial cumin) in Hindi, as سیاہ زیرہ (syah zirah, black cumin), کالا زیرہ (kaala zirah, black cumin), and زيره كوهی (zirah kuhi, mountain/wild cumin) in Urdu, زيره كوهی (zireh kuhi, wild cumin) in Persian, and сиёх дона (siyoh dona, black seed) in Tajiki, and in Malayalam "സഹജീരകം".
The commonly used Hindi term shahi zeera may be a distortion of syahi (black in Persian) zeera. However, in the Hindustani language, the term syahi also means "inky black". In Bengali, kalo zeera also means black cumin, but refers to Nigella, not B. bulbocastanum. Nigella is widely used as a spice in Bengali food, while B. bulbocastanum is used rarely.
The plant is native to Europe.<ref name="POWO_838875-1">Template:Citation</ref> It reaches about Template:Convert tall and Template:Convert wide, bearing frilly leaves and hermaphroditic flowers; it is pollinated by insects and self-fertile.Template:Citation needed
Template:Unreferenced section The plant bears small-sized seeds and one can pluck them once the plant is very dry. Not more than 5 to 8 g can be plucked from each plant, contributing to the high price of $2 per 10 g (1987 rates).
The seeds are most valued as a garnish to high value, very special Indian dishes; they should not be ground, as their flavor would be reduced.