Agaves form rounded mounds, called rosettes, of tough, thick, toothed, water-retentive leaves. They are often called century plants because of the popular
belief that they live a century before flowering, and this isn't far from the truth, from 7 to as much as 60 years. Agaves are natives of deserts in the American southwest and Mexico, and sometimes have
very small natural ranges. Don't miss this great Agave Page.
DESPERATE MEASURES
"Agave" means "noble." Imagine you're an agave, and your job is to grow and prosper in the desert. Nobody said it would be easy. Way too much heat and light, never enough water. The desert won't support much plant life or much biodiversity. The nearest agave of your species might be a hundred yards away; the nearest flowering agave could be ten miles distant. You're a lone warrior. Somehow you need to get pollen to or from another compatible agave.
And there's another problem. Water and nutrients are so limited that you grow very very slowly. You can't begin to think about flowering when it takes most of your resources just to survive.
You need some sort of beacon, something that no pollinator could miss. So you do something truly extraordinary. You store energy gradually as you grow over the course of up to 60 years. Then, all at once, you erect a towering flower stalk, four to eight times taller than the entire plant. On the top, a flaming pyre of bright yellow flowers, tinged with red.
Pollinators flock in from miles around. You've done your job, invested a lifetime of stored energy. And then you die. Agaves aren't the only plants that are monocarpic—flowering once and then dying—but they are among the most dramatic.
Agaves' approach to the rigors of desert habitats is mirrored by
several other plant groups, including yuccas and aloes. This is an example of convergent evolution,
where unrelated species evolve similar forms because they are the best adaptation to their
habitats.
(Agave) · 2/26/2010 · San Diego Zoo, San Diego, California ID is dubious
Rosette is relatively large, 6-10' (1.8-3 m) around . Perhaps the most iconic agave, the one people most think of as the "century plant."
Rosettes are 4-6' (1.2-1.8 m) high and 6-10' (1.8-3 m) around.
Rosettes are 12-19" (30-48 cm) high and 16-24" (40-60 cm) around.
Flowers
Yellow blooms appear on stalks 16-26' (5-8 m) high, branched at the top into 15-35 branches.
Yellow blooms appear on stalks 16-26' (5-8 m) high, branched at the top into 15-35 branches.
Flowering stalks are 6½-13' (2-4 m) tall. Individual flowers are yellow, 1-2" (3-6 cm) long, appearing from March to July.
Leaves
Leaves are 3-6½' (1-2 m) long and 6-10" (15-25 cm) wide. They are smooth and very rigid, gray-green or bluish, with dark brown teeth along the edges.
3-6½' (1-2 m) long and 6-10" (15-25 cm) wide. They are smooth and very rigid, gray-green or bluish, with bold white stripes and dark brown teeth along the edges.
8-16" (20-40 cm) long and 1¾-3" (5-8 cm) wide, grayish or bluish green, with toothed edges, and often with bands of varying color across the width of the leaves.
Rosettes are 8-10' (2.4-3 m) around. Found in Antigua and Barbuda.
Rosette is 10-18" (25-45 cm) tall and 16-27" (40-68 cm) around, composed of 8-60 leaves, but usually around 20. It often produces "offsets"—new nearby plants.
Flowers
Flowering spike is up to 18' (5.5 m) feet high, multiply branched near the top. Flowers are yellow. Baby plants form in place of the spent flowers.
Flower stalk is 6½-16' (2-5 m) high, blooms with red- or purple-shaded yellow flowers.
Leaves
Dagger-like, medium green, up to 3' (1 m) long, with sharp tips and small teeth along the edges.
Thick, curved, and tipped with sharp spines (hence the name "shin dagger"). They have irregularly spaced teeth on the leaf edges.
Rosettes are small, symmetrical blue-gray balls are 30-36" (76-91 cm) in diameter.
Rosettes reach 24" (60 cm) tall and 3' (91 cm) around, and resemble giant artichokes.
Rosettes reach 24" (60 cm) tall and 3' (91 cm) around, and resemble giant artichokes.
Flowers
Flower spike 9½-13' (3-4 m) high, split into 12-15 branches at the top; the open flowers are yellow, tinged with red or purple.
Stalk is 11-20' (3.4-6.1 m) high, with 18-30 branches, each with bright lemon yellow flowers. Flowering is from June to August.
Leaves
Leaves are short, wide, nearly round, with spines along the edges. The leaves are textured with patterns and color variations that look like impressions from nearby leaves.
10-16" (25-40 cm) long and 3-5" (7.6-12 cm) wide, wide and flat or somewhat oval in shape, tapering to a sharp dark tan, brown, or black tip. They are smooth and rigid, about ½-¾" (1.3-1.9 cm) thick, edged with teeth, light grayish- or bluish-green.
10-16" (25-40 cm) long and 3-5" (7.6-12 cm) wide, wide and flat or somewhat oval in shape, tapering to a sharp dark tan, brown, or black tip. They are smooth and rigid, about ½-¾" (1.3-1.9 cm) thick, edged with teeth, light grayish- or bluish-green.
Small, 4-6" (10-15 cm) tall and 6-8" (15-20 cm) around. They may be solitary plants or growing in dense tufts that probably originated from a single plant.
5-6' (1.5-1.8 m) tall and 9½-13' (3-4 m) wide, with 20-30 leaves at the base.
Rosettes can reach 3' (91 cm) in height and 5' (1.5 m) around. Plants may produce offsets, forming colonies.
Flowers
Yellow flowers appear atop a spike 3-6' (91-182 cm) tall.
Stalks are 23-26' (7-8 m) high, branched near the top into 15-20 branches.
Stalk is up to 12' (3.7 m) high, with branching flowers at the top that are yellow or reddish.
Leaves
2-4" (5-10 cm) long and less than ½" (1.3 cm) wide, dark green, with white imprints from the bud. Short, curly white filaments like those in yuccas are present.
3-6½' (1-2 m) long and 10-14" (25-36 cm) wide, dark green to bluish gray-green. Leaf edges have fairly large teeth.
Leaves are up to 24" (60 cm) long and 10" (25 cm) wide. Teeth may or may not be present along leaf edges, varying even in a single plant.
Plants look like hedgehogs, with hundreds of densely packed leaves, and often grow in colonies. Forms rounded mounds up to 24" (60 cm) high and 3' (1 m) around.
Rosette is 4-6' (1.2-1.8 m) tall. Unlike most agaves, the rosette is on top of a very short stem, less than 6" (15 cm) tall and looking a little like a crushed pineapple. Commonly cultivated for tequila and as a natural sweetener, also popular with gardeners.
Rosettes are fairly small, 20-28" (50-70 cm) around. They consist of a tight ball of stiff leaves with white edges.
Flowers
Spike is crooked, 5-8' (1.5-2.4 m) tall, with reddish-purple flowers that bloom between July and August.
Spike is 16-20' (4.9-6.1 m) tall, with 20-25 branches. Flowers are green, with red stamens.
Spike 10-13' (3-4.0 m) high, the upper half of which contains cream-colored flowers, with a touch of red/purple.
Leaves
10-20" (25-50 cm) long and ¼-½" (6.3-12 mm) around. In cross section, the leaves are rhomboidal: like a skewed rectangle, but with top and bottom depressed. Flowers form crooked spikes up to 8' (2.4 m) in height.
Rigid, swordlike, blue-gray or green-gray leaves form a nearly perfect circle. Leaves are lined with regularly spaced teeth, and are 35-47" (88-119 cm) long and 3-5" (7.6-12 cm) wide.
Triangular in cross-section, 6-8" (15-20 cm) long and 1½-2½" (3.8-6.3 cm) wide.
ID is dubious 
