Alocasia longiloba
| Alocasia longiloba | |
 | |
| Classification | |
| Group: | Angiosperms |
|---|---|
| Order: | Alismatales |
| Family: | Araceae |
| Genus: | Alocasia |
| Species: | A. longiloba |
| Classified: | Miq., 1856 |
| Growing | |
| Propagation: | From From division, seeds, bulbils |
| Adult size: | 0.5m-1m |
| Lighting: | Medium |
| Watering: | Keep the soil slightly moist but not wet |
| Fertilization: | Monthly during active growth |
| Soil: | Well drained |
| Humidity: | High humidity preferred, low humidity tolerated |
| Other information | |
| Toxicity: | Toxic sap |
| Rarity: | Rare |
| See more Alocasia | |
Common names:
(incorrectly) Alocasia watsoniana
Alocasia longiloba is a flowering plant of the Araceae family, typically grown for its distinctive 'elephant ear' foliage. Native to China and east Asia.
Contents
Name
Alocasia comes from the Greek 'a' meaning without and 'Colocasia' the name of a closely allied genus, from which it was separated.
Longiloba is from the Latin words longus meaning "long" and lobus meaning "a rounded projection or protuberance" referring to the leaf shape.
Characteristics
Foliage
A. longiloba has grey-green leaves with white veining. The leaves are held on burgundy petioles.
These leaves emerge from an underground corm. A corm is the swollen base of a stem axis enclosed by dry scale-like leaves that form a protective shell.
Cultivars
Alocasia amazonica 'Polly'
Alocasia amazonica 'Polly' is a hybrid of A. sanderiana and A. longiloba.
Flowers
The A. longiloba inflorescence consists of an erect spadix enclosed in a green, boat-shaped spathe. The corn-like spadix is covered in small flowers.
Care
A. longiloba wants bright, indirect light. It can tolerate some direct light but avoid hot midday sun or the leaves will scorch.
Use a well draining soil mix (see aroid soil), amended with more moisture retentive potting mix than for most Aroids and water thoroughly, allowing excess to drain. Alocasia do like more constant moisture than most Aroids but a waterlogged soil will lead to root rot.
Alocasia are unusually sensitive to low temperatures in the home. In winter with low light and low temperatures near windows they can enter a dormancy, so it is best to avoid placing them in an unheated room or near to a cold window. Dormancy will involve the plant dropping all its leaves and existing as an underground corm. If you push your finger down into the soil and feel the underground corm it should feel firm and not squishy. If the plant enters dormancy happens you can force the plant out of dormancy. This is a similar process to propagating Alocasia from a bulbil.
Common issues
Dropping leaves after bringing the plant home
Alocasia are a temperamental genus of plants. Moving them from the hot, humid and ideal conditions of a nursery to your dim and dry home can be stressful, and the plant will respond by dropping old leaves to preserve resources. After a few weeks the plant should stabilise at between three and five leaves at any one time.
Yellowing/floppy leaves
Unlike many other plants, yellowing and dying leaves on Alocasia isn't a sure sign that there are issues. Alocasia only hold a certain number of leaves at any one time, dependent on the health and size of the root system.
If your A. longiloba produces a new leaf at the same time as losing the oldest or outmost leaf on the corm then this is natural and nothing to worry about.
Overwatering
If the soil is staying moist for more than two weeks between watering, or the soil feels soggy or very wet after a week then consider repotting the plant into a smaller container: the roots staying wet for too long will lead to root rot and a quick decline in the plant's health. When repotting use a mix that drains well but retains some moisture (see aroid soil)
Sun damage
A. longiloba cannot take direct sun, except in the early mornings or late evenings. Make sure it is situated away from parts of the home that get direct, hot midday sun.
Dormancy
If your Alocasia drops all its leaves it may be a sign it has entered dormancy. This is a natural way the plants can cope with colder winter weather. Unlike Caladium this dormancy is not seasonal and can be avoided by keeping the plant somewhere warm (above 15C/60F) throughout the coldest months of the year.
To test that the plant has entered dormancy and hasn't just died, push your finger down into the soil and feel the underground corm, which should be firm and not squishy or rotten.
To bring the plant out of dormancy take the plant pot and place it in a sealed plastic bag. Put this bag somewhere relatively hot within your home - an airing cupboard or on top of a book on a radiator. Make sure to check the soil every other day and keep it slightly moist around the corm and air out the bag, removing any condensation to avoid rot. After around two weeks you should see a new leaf bud appearing at the top of the corm and at that point you are safe to move the plant back to its place within your home.
Pests
A. longiloba can be affected by spider mites, mealybugs, scale, thrips and whitefly.