We’ve noticed an increased interest in a particularly pretty plant group. This week we’re exploring the wild and wonderful world of Alocasias. We’ll start with an overview of the genus and then touch on some of the capable cultivars and spectacular species that make up this charismatic collection of plants.
Made up of 97 accepted species and a handful of hopefuls, the genus Alocasia is almost entirely native to tropical and subtropical Asia as well as eastern Australia. Plants can be found growing in rainforests, secondary vegetation sites, and along streams or marshy places. A few species, including macrorrhizos, odora and plumbea, have even naturalized in the southern United States; mostly in southern Florida. As members of the Araceae family, they are rhizomatous (having horizontal underground plant stems capable of producing the shoot and root systems of a new plant) or tuberous (having a much thickened underground part of a stem or rhizome, serving as a food reserve and bearing buds from which new plants arise), broad-leaves, perennial, flowering plants. The genus sports long-stalked, arrowhead-shaped to heart-shaped leaves, often dramatically decorated and colorfully adorned. Alocasias range in size, depending upon species, from 8” to 36” long. It’s these luxuriant leaves that have captured our hearts and secured these plants’ place in our homes and hearts. Like their Araceous cousins, Alocasia’s inflorescence (the complete flower head of a plant including stems, stalks, bracts, and flowers) is made up of a spathe (a large sheathing bract enclosing the flower cluster) and spadix (a spike of minute flowers closely arranged around a fleshy axis). Flies of the genus Colocasiomyia are their main pollinators. The inflorescence offers a safe space for flies to lay their eggs and the developing larvae eat the decomposing spadix tissues without damaging the young seeds. Not without its own safety net, Alocasias are laticiferous plants containing a toxic latex made up of raphid or raphide (needle-shaped) crystals of calcium oxalate along with other irritants (possibly including proteases) that can numb and swell the tongue and pharynx. This can cause difficulty breathing and sharp pain in the throat. While the leaves and stems bear plenty of these toxins, the lower parts of the plant contain the highest concentrations of the poison.
General care is as follows, but keep in mind that each species will have a few of its own particular needs.
Light – direct, eastern or western light if kept indoors (species dependent); morning sun to dappled shade if planted outdoors (species dependent)
Air – avoid A/C, heater, and doorway drafts
Water – allow soil to lightly-fairly dry between waterings
Food – routine feeding during the growing period
Soil – loose, well-draining soil
Maintenance – regular leaf cleaning and pest checking
Minimum temperatures – 60F, plants will begin to drop leaves and enter dormancy if kept below this temp for a week or more
Alocasia reginula ‘Black Velvet’
A miniature jewel Alocasia with characteristic dark foliage and a compact growth habit. Named for both its regal appearance and black velvety leaves, which are contrasted beautifully by the piercing white venation.
Alocasia 'Pink Dragon'
Its green leaves have its family’s classic broad shape and feature dense white veins and purple-hued undersides. The stunning color beneath the leaves is an adaptation to the mottled light of its native Asian rainforest floor. Named for its distinctive pink stems.
Alocasia ‘Sarian’
A hybrid of Alocasia zebrina and A. micholitziana. It was named for Zac B. Sarian, an agricultural journalist from the Philippines.
Alocasia amazonica ‘Bambino’
A dwarf variety of the already relatively small Alocasia amazonica that tops out at around 12″ tall.
Alocasia cuprea ‘Dewey’s Reversa’
The leaves have a metallic shimmer to them with a magnificent range from coppery-green to deep red and even black.