Camas is well-known for its edible qualities and is an obvious candidate. But another bulb, the extravagantly exotic tiger flower (Tigridia pavonia), must surely be the dark horse in any race to get bulbs onto your plate. It's a well-known Mexican plant, quite easily grown, with ridiculously large and opulent flowers for its stature. These open in the middle of the day and seem to close just before you get home from the daily grind - a particularly annoying trait in view of their spectacular beauty. Luckily, the flowers appear during the summer over a period of several months, so odds on you'll get the chance to see them in all their glory on a few occasions.
Tiger flower bulbs are often sold in the pile-it-high-sell-it-cheap supermarkets at this time of year, although I wouldn't advise eating these - plant them and consume their progeny after a couple of seasons' detox in your own garden. As plants they're certainly much hardier than received wisdom suggests and the bulbs happily survive the erratic cycles of wet and cold weather that typify our winters here.
For all its gaudy allure, this is a plant that seems to be adept at generating a considerable amount of confusion and misinformation. Tigridia, as is pretty obvious, is derived from the tiger, an allusion to the stripes in the flowers. Except they're not stripes, they're spots. The Aztecs, who knew the plant well, referred to the flowers in Nahuatl as oceloxochitl, which means - no, not ocelot, but jaguar flower. At least both the ocelot and jaguar are spotted New World cats - a definite improvement on tiger. I can only assume that European prejudices about the superiority of Old World felines influenced the decision to elect the tiger Top Cat when bestowing names on new plants.
The bulbs (not corms as is often stated) were a familiar foodstuff to the Aztecs and were known as as cacomitl. This has nothing to do with and should not to be confused with the cacomistle, a raccoon-like animal with which the Aztecs were also acquainted and whose name is derived from yet another Nahuatl word. And to top it all, Tigridia is also a single species genus of Nymphalid butterfly found in Mexico and South America. Thankfully, that does at least have stripes.Cacomitl bulbs have a pleasant, sweet flavour and floury texture when cooked, quite similar to a sweet chestnut - but don't eat them raw. Like the jaguar, they bite. I was tempted to try one straight out of the ground, but at the last moment, discretion overcame my valour. I would be interested to know what causes the nasty sensation of burning mouth and throat that will surely ensue should you be braver than me. I wonder whether they contain those vicious needle-like calcium oxalate crystals that you find in some other roots and tubers, notably taro. Cooked, however, they're like a lion tamed; I've had them both boiled and baked and they certainly make good eating.
The bulbs produce large numbers of offsets and if you dig up the clumps every couple of years, you can eat the spare ones. Yield and bulb size are not spectacular, but there's something quite satisfying and subversive about converting ornamentals into edibles on the sly.
As might be expected, I'm by no means the first person to explore the potential of cacomitl in recent times. Ken Fern, in his excellent book, Plants for a Future, describes their ease of cultivation and propensity to self-seed in a Cornish garden not so far from my own.
More surprising is Luther Burbank's interest in their potential as a food. Burbank was a prolific plant breeder who developed hundreds of varieties of ornamental and edible crops at his trial grounds in Santa Rosa, California. I can do no better than quote the "Plant Wizard" himself, from his 12 volume 1914 book 'Luther Burbank: His Methods, Discoveries And Their Practical Application'. In Volume 10, Chapter 3, 'Tigridia and Some Interesting Hybrids. New Charms in Faraway Flowers', he has this to say:
The development of the bulbs of the tigridias has not been at all a matter of accident. At all stages of the experiment in hybridizing and selection, I have paid the most careful attention to the condition of the bulbs, selecting always those that were largest, firmest and soundest. And the reason for this was not merely that such bulbs usually produce the best flowers, but also that it is worth while to improve the size and quality of the bulbs quite on their own account.
The particular reason for this is that the bulbs of the Tiger Plant are edible. When cooked like potatoes, or made into a stew, they constitute a really delicious vegetable.
To my taste the bulb of the tiger plant is at least the equal of any vegetable under cultivation. It is also highly nutritious. I am not sure that it has an equal among the vegetables of our gardens in its combination of nutritiousness and appetizing flavor.
No one to my knowledge has ever said that about mashua. Or oca.
Burbank was interested in Tigridia for both its ornamental and edible qualities, but I'm not so worried about the flowers myself; if they were a quarter of the size and the bulbs four times bigger, that would be, to my mind, an acceptable trade-off. After all, the heart doesn't crave flowers when the belly lacks bulbs.