Cumin Confusion: Black Seed, Black Cumin, Kalijiri and Kala Jeera

The confusion among cumin, black cumin, black seed, kala jeera and kalijiri is a great example of why we should use botanical names, not common names, even in recipes.  By the time the spices reached the English, the culinary names were totally screwed up. And if you buy Kalijiri instead of Kala Jeera, your curry will be disgusting.

Let's start with the edible spices:
Cumin (Cuminum cyminum) :  The classic Tex-Mex, Middle Eastern, and Indian spice.  Cumin is beloved by some for its warm earthy flavor, hated by others because to them it tastes like dirt.
The seeds are plump, slightly curved cylinders, ridged and light brown to yellowish tan. 

Cumin Seeds close up
By Chaitanya B D
https://commons.wikimedia.org/w/index.php?curid=5244056

Kala Jeera (Bunium bulbocastanum):  Kala Jeera is used in northwest India (Kashmir and Punjab), Afghanistan and Iran, mostly, as a spice.  It is popular in Moghul style recipes, giving a nutty flavor after it is cooked.  I haven't tried it yet.

The seeds are dark brown, slender and curved, with ridges.

Black Cumin Seeds
By Badagnani
https://commons.wikimedia.org/w/index.php?curid=3487490

Both species are members of the Apiaceae or Umbelliferae, a family of mostly aromatic flowering plants commonly known as the celery, carrot or parsley family. Other members are caraway, dill and fennel.

Kalonji (Nigella sativa) -Called Kalonji in India, and Charnushka in other places, for some silly reason it became known as "black cumin" even though it neither looks nor tastes like it.  Nigella reputedly tastes like a combination of onions, black pepper and oregano. 
The seeds are matte black and almost as wide as they are tall. They look a lot like the charcoal bits used in aquarium filters.

Kalonji or Charnuska Seeds

Nigella is in the Ranunculaceae (buttercup or crowfoot) family.
As "black seed" the oil from Nigella sativa is currently the subject of a lot of wild health claims with little to back them up.

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And then we come to the other seeds from India that are dark and pungent: kalijiri.

DO NOT COOK WITH THIS! It is vile!

Kalijiri (Vernonia anthelmintica) - See the spelling?  Kali is not Kala and Jiri is not Jeera.   In the various languages of India the names are distinctly different, but when spelled phonetically for English labels it gets confusing. This may be seen as "bitter cumin" on some websites.  If you are shopping in a speciality market, it's going to be with the medicinal herbs, not the curry spices.

The seeds are small, dark brown, tapered and flat on one end, not curved cylinders like cumin and black cumin  (no pictures yet).   Kalijiri is intensely bitter, pungent, and may cause nausea. 

Kalijiri is a member of the Asteraceae or Compositae (commonly referred to as the aster, daisy, composite, or sunflower family).  It is often listed on herbal medicine sites as "Centratherum anthelminticum (L.) Kuntze ex Gamble"  which is an older synonym of Vernonia anthelmintica (L.) Will
Kalijiri is used as a post-partum tonic in parts of India, according to blogger Shireen Sequeira, whose blog has many edible recipes from the area around Mangalore, and then the tonic.  She calls it "a deadly black & bitter decoction" and that's what it is. 
The more common modern use is as part of a "weight loss" regimen with methi (fenugreek, or Trigonella foenum-graecum ) and ajwain (Carum copticum) ... that combination will certainly kill your appetite.