Culantro may look like a misspelling, but it's not. Also called 'sawtooth herb' (because its long leaves have serrated edges), culantro is similar in taste and smell to coriander, which is known in some parts of the world as cilantro.
However, culantro has a more powerful taste and a much sturdier texture than the delicate leaves of fresh coriander, and the flavour remains even when cooked over a long period. It's a popular herb in Southeast Asia, Latin America and the Caribbean. In Vietnam, many restaurants specialising in pho include culantro as part of the fresh herb platter that's served with steaming bowls of beef or chicken noodle soup.
Culantro is fairly easy to grow - you can buy the plant at gardening shops specialising in culinary herbs. Snip off the leaves as needed, but before they turn yellow, wrap them in cling-film and freeze for later use. Remove seed stalks if you want to encourage more leaves to grow, or harvest the seeds and plant them.
I like to use the herb in a marinade for flank steak. Roughly chop the leaves and pound them in a mortar with shallots and garlic. Add fresh orange and lime juice, freshly ground black pepper and a splash of soy sauce. Marinate the steaks for about an hour (or more in the fridge), pat dry with paper towels and grill over hot coals.