I think Jim Shields' original phrase was "major agricultural crops" which
implies an effort to cultivate them. People think of corn, beans, chiles
(capsicum) and squash here in the Southwest but research by Wendy Hodgson
at the Desert Botanical Garden in Phoenix, and others, strongly suggests
various Agave cultivars/species were planted (not harvested from the wild)
for food. Search on Wendy's name for a link to her fantastic book _Food
Plants of the Sonoran Desert_, which includes some bulbs.
Several Agave species are known only from ridges overlooking floodplains,
immediately adjacent to building ruins. These species share several
characteristics eminently suitable for food crops: they bloom early for
Agave, usually in less than 10 years; they are small to medium sized
plants; they have fewer marginal teeth than wild plants, thus easier to
manage; they are very sweet and delicious when cooked; they offset
profusely and usually produce tens of thousands of small plantlets called
bulbils on the inflorescence rather than fruits, thus permitting a more
rapid harvest cycle.
The floodplains supported the wetter crops while the Agave grew without
irrigation above them. Rain is sporadic here, and some years there is not
enough to support corn, beans and squash production. In a good-sized
population some individual Agave plants will bloom each year without
regard to the rain. The Agave fields at the sites studied are large enough
to have provided most of the calories for the people who lived at the
sites.
These localities are often widely dispersed and one species (whose name
escapes me right now) is known only from two sites in northern Arizona and
one in Mexico, all three adjacent to ruins. Some Agave are too stringy,
too sour, or too bad-tasting to eat; these are never found in similar
sites. The stringy ones are now cultivated worldwide for fiber, but
originated in Mexico. There are at least a dozen different Agave, some
undescribed, from these human associated localities.
Agave are harvested just as they prepare to bloom, when there is a
maxiumum of starch in the stem. The leaves are trimmed off and the
remaining stem roasted in a rock-lined pit for 3 days. After removal and
cooling the stem is sliced and eaten or dried for storage. The starch
mostly turns to sugar.
I have eaten roasted Agave potatorum. It was sweeter than most any fudge I
have eaten in my life. This species is still wild-harvested rather than
cultivated because it does not offset and does not produce bulbils. It
must be grown from seed, a lengthy undertaking. In central Mexico is
fermented and distilled into the liquor mezcal.
If you are driving through central-southern Mexico and see a mezcal stand
at the side of the road, by all means stop and visit. It will feature a
shade structure housing the fermenting tank and still, and a tilted,
curbed, stone-paved threshing station with grinding wheel where a burro is
yoked to the grinding wheel and turns in circles to crush the cooked Agave
stems, whose juice runs through a break in the curb into a vessel. The
proprietor will be happy to show you how he makes the liquor, offer you
substantial samples, and sell some to you. There is good mezcal and there
is really bad mezcal. Caveat emptor.
Tequila is made from cultivated A. tequilana ("the blue agave"), distilled
only in the state of Jalisco. Distilled elsewhere it is called mezcal. It
may be grown anywhere and much of it is now grown in other Mexican states.
A. tequilana is now considered a variety of A. angustifolia, which is by
far the most widely dispersed Agave species in the wild, throughout
Mexico. All subspecies offsets profusely and produce bulbils rather than
fruits. Vast fields are planted with bulbils to be harvested 3-5 years
later for liquor production.
Agave murpheyi is one of the Arizona food agaves. It is extremely rare in
the wild but is a very common Phoenix landscape plant. It offsets
profusely, produces bulbils rather than fruits, is small for an Agave and
tolerates overnight temperatures down to 10 Fahrenheit / -12C if grown on
well-drained soil. I don't think it would do well in a freezing wet winter
but then I haven't tried it. Agaves are great in pots. My plant has many
dozen small offsets (under 3" tall and wide.) Search on it to find some
pictures. If Dell would accept them and if any of you would like me to
send some for the BX, let me know. They are not bulbs, though.
I grow Agave tequilana too. When it flowers and sets bulbils I'll offer
those to the BX too.
Leo Martin
Phoenix Arizona USA