Alstroemeria

Distribution and habitat

The genus Alstroemeria is exclusively native to South America, with various species found ranging from Venezuela (3° north of the Equator), to Tierra del Fuego, Argentina (53° South). Within this range of the entire genus, two centers of species diversity are recognized, one in Brazil and one in Chile.

In Chile, Alstroemeria is amongst the most diverse genera of vascular monocotyledons, with more than 50 recognized or accepted taxa (species, subspecies and varieties). Of these taxa, roughly 80% are endemic to the Mediterranean matorral zone of central Chile.

In Brazil, which is home to more than 40 species, most Alstroemeria species are found outside of the Amazonian region, and are concentrated towards the south and east of the country. Alstroemeria can be found in almost all types of habitat, from forests to savannahs, caatingas to swamps, and commonly, high altitude grasslands and rocky outcrops, with typical altitudes ranging from 300m in the Amazon, to 2300m in the Itatiaia National Park. Most Brazilian species have relatively restricted distributions.

Taxonomy

The genus was described by Johan Peter Falk and his thesis supervisor Carl Linnaeus in his 1762 dissertation Planta Alströmeria. Linnaeus bears the botanical authority (L.).

Etymology

The genus was named after the Swedish baron Clas Alströmer (1736–1794), a friend of Linnaeus. The family name Alströmer is itself a botanical one: Swedish al ("alder") + ström ("stream").

Cultivation and uses

Many hybrids and at least 190 cultivars have been developed, featuring many markings and colors, including white, yellow, orange, apricot, pink, red, purple, and lavender. The most popular and showy hybrids commonly grown today result from crosses between species from Chile (winter-growing) with species from Brazil (summer-growing). This strategy has overcome the florists' problem of seasonal dormancy and resulted in plants that are evergreen, or nearly so, and flower for most of the year. This breeding work derives mainly from trials that began in the United States in the 1980s; the main breeding is done nowadays by companies in the Netherlands. The flower, which resembles a miniature lily, is very popular for bouquets and flower arrangements in the commercial cut flower trade. These delicate flowers survive up to 14 days in water without any signs of shrivelling.

Most cultivars available for the home garden will bloom in the late spring and early summer. The roots are hardy to a temperature of 23 °F (−5 °C). The plant requires at least six hours of morning sunlight, regular water, and well-drained soil.

AGM cultivars

The following cultivars have gained the Royal Horticultural Society's Award of Garden Merit, all with a hardiness rating of H4 (Hardy – average winter −10 to −5 °C (14 to 23 °F)) apart from 'Friendship' (H5: Hardy – cold winter −15 to −10 °C (5 to 14 °F)):

• 'Apollo' (white/yellow flowers, 100 cm)
• 'Cahors' (pink/yellow, 90 cm)
• 'Coronet' (salmon/yellow flowers, 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 flowers, 120 cm)
• 'Yellow Friendship' (140 cm)

Ecology

Some alstroemerias have escaped cultivation and become weeds, such as Alstroemeria pulchella. and A. aurea, which are now weeds in Australia.

Species