Alstroemeria

Alstroemeria, known as the Peruvian lily or lily of the Incas, belongs to the plant family Alstroemeriaceae. Its species are all native to South America, though some have spread and become naturalized in places like the United States, Mexico, Australia, New Zealand, Madeira, and the Canary Islands.

Most species are found in one of two main regions: central Chile and southern Argentina, or eastern Brazil. Those from Patagonia grow during winter, while Brazilian species grow in summer. Nearly all are long-lived perennials, except for A. graminea, a small annual from Chile’s Atacama Desert.

Description

The plants grow from clusters of tubers, producing both fertile and sterile stems. Fertile stems can reach 1.5 meters tall in some species. Leaves are arranged alternately and are resupinate—twisted on their stalks so the undersides face upward.

Leaf shapes vary, and the blades have smooth edges. Flowers appear singly or in umbels, with six petals up to 5 centimeters long. Colors include red, orange, yellow, green, purple, pink, and white, often flecked, striped, or streaked with darker shades.

Each flower has six curved stamens and a three-lobed stigma. The fruit is a capsule with three valves. As an inferior monocot, the petals sit above the ovary, and the leaf veins run parallel.

Distribution and habitat

Alstroemeria is found only in South America, from Venezuela (about 3° north of the Equator) down to Tierra del Fuego, Argentina (53° South). Within this range, two diversity centers stand out: Brazil and Chile. In Chile, it is one of the most diverse genera of vascular monocots, with over 50 recognized species, subspecies, and varieties. About 80% of these are unique to central Chile’s Mediterranean matorral zone.

Brazil hosts more than 40 species, mostly outside the Amazon, concentrated in the south and east. They live in many habitats—forests, savannahs, caatingas, swamps, and especially high-altitude grasslands and rocky outcrops—at elevations from 300 meters in the Amazon to 2,300 meters in Itatiaia National Park. Most Brazilian species have limited ranges.

The genus was first described by Johan Peter Falk and his advisor Carl Linnaeus in a 1762 dissertation, Planta Alströmeria. Linnaeus holds the botanical authority (L.). The name honors Swedish baron Clas Alströmer (1736–1794), a friend of Linnaeus. The family name Alströmer itself comes from Swedish al (alder) and ström (stream).

Cultivation and uses

Many hybrids and at least 190 cultivars exist, offering colors like white, yellow, orange, apricot, pink, red, purple, and lavender. Popular showy hybrids come from crosses between Chilean (winter-growing) and Brazilian (summer-growing) species. This approach solved the problem of seasonal dormancy, producing plants that are nearly evergreen and bloom most of the year. Breeding work began in the United States in the 1980s, with major efforts now led by companies in the Netherlands.

The flowers, resembling miniature lilies, are popular in bouquets and cut flower arrangements, lasting up to 14 days in water without shriveling. Most garden cultivars bloom in late spring and early summer. The roots tolerate temperatures down to 23°F. Plants need at least six hours of morning sun, regular water, and well-drained soil.

AGM cultivars

Several cultivars have received the Royal Horticultural Society’s Award of Garden Merit, all rated H4 (hardy to -10 to -5°C) except ‘Friendship’ (H5, hardy to -15 to -10°C). These include ‘Apollo’ (white/yellow, 100 cm), ‘Cahors’ (pink/yellow, 90 cm), ‘Coronet’ (salmon/yellow, 140 cm), ‘Friendship’ (yellow flushed pink, 100 cm), ‘Orange Glory’ (150 cm), ‘Oriana’ (salmon/yellow, 50 cm), ‘Phoenix’ (red/yellow, 100 cm), ‘Red Elf’ (100 cm), ‘Sirius’ (pink/yellow, 100 cm), ‘Sonata’ (red/yellow, 100 cm), ‘Spitfire’ (orange/yellow, 90 cm), ‘Tessa’ (red, 120 cm), and ‘Yellow Friendship’ (140 cm).

Some alstroemerias have escaped gardens and become weeds, including Alstroemeria pulchella and A. aurea, which are now invasive in Australia.