Also known as: Butter pear, Alligator Pear, Aguacate, Palta

Avocado is native to the Caribbean, Mexico, South America and Central America. The avocado is a dense, evergreen tree, shedding many leaves in early spring. It is fast growing and can with age reach 80 feet, although usually less, and generally branches to form a broad tree.

Avocados are a commercially valuable crop whose trees and fruit are cultivated in tropical climates throughout the world (and some temperate ones, such as California), producing a green-skinned, pear-shaped fruit that ripens after harvesting. The fruit (technically a large berry) of the tree that contains a pit (hard seed casing) which may be egg-shaped or spherical.

Growth is in frequent flushes during warm weather in southern regions with only one long flush per year in cooler areas. Injury to branches causes a secretion of dulcitol, a white, powdery sugar, at scars.

Roots:

Roots are coarse and will raise pavement with age. Grafted plants normally produce fruit within one to two years compared to 8 - 20 years for seedlings.

Leaves:

Avocado leaves are alternate, glossy, elliptic and dark green with paler veins. They normally remain on the tree for 2 to 3 years. The leaves of West Indian varieties are scentless, while Guatemalan types are rarely anise-scented and have medicinal use. The leaves of Mexican types have a pronounced anise scent when crushed. The leaves are high in oils and slow to compost and may collect in mounds beneath trees.

Flowers:

Avocado flowers appear in January - March before the first seasonal growth, in terminal panicles of 200 - 300 small yellow-green blooms. Each panicle will produce only one to three fruits. The flowers are perfect, but are either receptive to pollen in the morning or shed pollen the following afternoon (type A), or are receptive to pollen in the afternoon, and shed pollen the following morning (type B). About 5% of flowers are defective in form and sterile. Production is best with cross-pollination between types A and B. The flowers attract bees and hoverflies and pollination usually good except during cool weather. Off-season blooms may appear during the year and often set fruit.

Fruits:

West Indian type avocados produce enormous, smooth round, glossy green fruits that are low in oil and weigh up to 2 pounds. Guatemalan types produce medium ovoid or pear-shaped, pebbled green fruits that turn blackish-green when ripe. The fruit of Mexican varieties are small (6 - 10 ounces) with paper-thin skins that turn glossy green or black when ripe.

The flesh of avocados is deep green near the skin, becoming yellowish nearer the single large, inedible ovoid seed. The flesh is hard when harvested but softens to a buttery texture. Wind-caused abrasion can scar the skin, forming cracks which extend into the flesh. "Cukes" are seedless, pickle-shaped fruits. Off-season fruit should not be harvested with the main crop, but left on the tree to mature. Seeds may sprout within an avocado when it is over-matured, causing internal molds and breakdown. High in monosaturates, the oil content of avocados is second only to olives among fruits, and sometimes greater.

Scientific classification:

Other species of Avocado include, Guatemalan (Persea nubigena var. guatamalensis L. Wms.), Mexican (P. americana var. drymifolia Blake), West Indian (P. americana Mill. var. americana). Hybrid forms exist between all three types.