This is from wikipedia:

Black cumin

"Original black cumin (Carum bulbocastanum) is rarely available, so N. sativa is widely used instead; (in India, Carum carvi is the substitute). Cumins are from Apiaceae or Umbelliferae (both names are allowed by the ICBN) family, but N. sativa is from Ranunculaceae family. Black cumin (not N. sativa) seeds come as paired or separate carpels, and are 3-4mm long. They have a striped pattern of nine ridges and oil canals, and are fragrant (Ayurveda says, "Kaala jaaji sugandhaa cha" (black cumin seed is fragrant itself), blackish in colour, boat-shaped, and tapering at each extremity, with tiny stalks attached; it has been used for medicinal purposes for centuries, both as a herb and pressed into oil, in Asia, the Middle East, and Africa. It has been traditionally used for a variety of conditions and treatments related to respiratory health, stomach and intestinal health, kidney and liver function, circulatory and immune system support, as analgesic, anti-inflammatory, antiallergic, antioxidants, anticancer, antiviral and for general well-being."

Anyway, I bought the Indian kalonji seeds and the size, color and taste is exactly like the black seeds I purchased before from the blessedseed site. If wikipedia is right, maybe none of my purchases was the original black cumin!

So, now I have to search for the rare Carum bulbocastanum?!! It seems easy to find gold! :)