Variations 
var. americana
This form of the species grows in the tropical lowlands of the West Indies and produces large fruit up to 3 kg (6.6lbs). The skin of the fruit has a lacquered bright green appearance and has the lowest oil content of all the varieties.

var. drymifolia
This form of the species is known as the Mexico race and naturally occurs in the subtropical Mexican highlands.  It has scented leaves produces small thick-skinned dark fruit.

var. guatemalensis
This form of the species in grows in the subtropical highlands of Guatemala and produces very large fruit with a warty brittle skin.

Cultivars
'Anaheim'
This West Indian cultivar forms a small three with large leaves and produces very large thick-skinned green fruit that matures during summer.  It is only suitable for subtropical climates, as it is cold sensitive.

'Booth 7'
This medium-sized tree is a hybrid between the West Indian and Guatemalan forms and produces a thick-skinned fruit that matures during autumn.

'Brogdon'
This large tree grows to 10 m (30ft) and is a hybrid between the West Indian and Guatemalan forms.  It grows well in warm temperate (zone 9) to tropical regions (zone 11) and produces small, purplish fruit that matures during mid summer.  It is commonly grown as a shade tree in large gardens or parks.

'Choquette'
This tree grows to 10m (30ft) tall with a spring crown and is a hybrid between the West Indian and Guatemalan forms.  It grows in sub tropical climates and has very large leaves and produces large green fruit that matures during winter.  Quality fruit is only produced in alternate years.

'Fuerte'
This large tree forms a six broad spreading crown and is a hybrid between the Guatemalan and Mexican form.  The smallish fruit is produced abundantly in alternate years and matures from winter to spring.  It is widely cultivated for its oily, nut flavoured flesh and is grown in sub tropical regions (zone 10 to 11).

'Gainesville'
This Mexican cultivar is upright or the spreading crown to 10 m (30ft) and produces abundant small, deep purple fruit during summer. It tolerates growing in warm temperate climates (zone 9) and regarded as the hardiest to cold.

'Hall'
This medium-sized tree is a hybrid between the West Indian and Guatemalan forms and has attractive large leaves.  It produces large green fruit that matures during autumn.

'Hass'
This large upright spreading tree is a hybrid between the Guatemalan and Mexican forms and grows in sub tropical regions (10 to 11).  It produces deep purple to black thick skinned, pear shaped fruit that matures from spring to summer.  The fruit is regarded as being delicious and is commonly cultivated.

'Hayes'
This large tree is upright or pendant branching and is a hybrid between the Guatemalan and Mexican forms.  It grows in sub tropical regions (zone 10 to 11) and produces purplish brown fruit that matures from winter to spring.

'Lula'
This tree is upright with a narrow crown and as a hybrid between the West Indian and Guatemalan forms.  It tolerates cooler conditions and produces large green fruit that matures from autumn to winter.

'Mexicola'
This tree grows to 30 feet of a spreading crown and as a cultivar of the Mexican form.  It grows in a warm temperate climate (zone 9) and produces small deep purplish to black fruit that mature from late summer to autumn.

'Monroe'
This tree is upright with a spreading crown and grows to 8m (25ft) tall.  It produces very large green fruit and is suitable for hot humid regions.  It is commonly planted in parks and large gardens as a shade tree tolerating a warm temperate to subtropical climate.

'Nabal'
This large tree is the Guatemalan cultivar and produces large green fruit that mature from early summer to autumn.

'Pinkerton'
This large spreading tree is a Guatemalan cultivar and produces a green fruit that matures from late winter to early spring.

'Pollock'
This tree is a West Indian cultivar and has a spreading, open habit and attains a height of 10 m (30ft).  It has large, glossy green leaves and produces green hair shaved fruit that matures during summer.  It is regarded as the most beautiful of all the varieties and is commonly planted as ornamental in parks or gardens.

'Sharwil'
This tree is a hybrid between the Guatemalan and Mexican forms and grows to 8 m (25ft) with an upright spreading crown. It produces large rough skinned fruit that matures from winter to spring.

'Simmonds'
This attractive large tree is a West Indian cultivar and grows to 12 m (40ft) tall.  It produces very large pear shaped fruit that matures from late summer to autumn.

'Taylor'
This upright three is a Guatemalan cultivar and has a spreading habit that forms a dense rounded crown. It grows in a subtropical climate (zone 10 to 11) and produces medium-sized green fruit that ripe from winter to spring.

'Tonnage'
This upright Guatemalan cultivar produces medium-sized green fruit that matures in late summer.

'Waldin'
This large tree grows to 16 m (50ft) and is a West Indian cultivar.  It grows in a subtropical to tropical region (zone 11 to 12) and has large attractive foliage.  The green fruits mature during late summer and the tree is planted in large gardens or parks as a specimen.

'Winter Mexican'
This attractive large tree is a hybrid between West Indian and Mexican forms.  The spreading crown consists of large a leathery leaves and the large green fruit mature from autumn to winter.

'Zutano'
This large Mexican cultivar grows to 12 m (40ft) tall, with glossy deep green leaves.  It produces green pear shaped fruit that is up to 150 mm (6in) long that mature during winter.