Ravenea rivularis
"
Ravenea rivularis is a beautiful tree no matter what size; however, it feels slightly overused as a houseplant or accent plant in the southern United States. Many of the guides selling these plants give advice on how to make sure the tree does not grow too tall, but I feel it would be more spectacular to let the tree flourish and grow to its natural height; and if there is not enough space to let it do that, another tree should be chosen in place of it.
"
Family |
Arecaceae |
Genus |
Ravenea |
Species |
rivularis |
Category |
Woody |
Type |
Tree (evergreen) |
USDA Hardiness Zone |
10a |
Canadian Hardiness Zone |
9b |
RHS Hardiness Zone |
H3 |
Temperature (°C) |
12.7 |
Temperature (°F) |
55 |
Height |
22 - 30 m |
Spread |
1 - 6 m |
General Description |
Ravenea rivularis is a fantastic ornamental tree, it has very attractive grey bark and very green leaves. When flowering, it displays beautiful panicles of white flowers that hang from the tree. The bark also has very prominent leaf scars, leaving rings along the bark every 4-10 centimetres. |
Landscape |
Ravenea rivularis is most commonly used as a houseplant. In the wild, it is mostly found in Madagascar. It can be used as an accent or vertical accent plant in tropical temperatures, and it has attractive grey bark that adds nice winter interest. Ravenea rivularis has narrow, pinnate leaves that add ornamental value. |
Cultivation |
Ravenea rivularis can grow in both full sun and partial shade, as it typically grows underneath a large canopy of other trees in the wild. Ravenea rivularis most commonly grows in very moist soils, sometimes with the bottom submerged in water; typically, it requires somewhat acidic soils. |
Shape |
Ravenea rivularis is an upright tree with a trunk that can grow up to 50 centimetres in diameter. It is a very symmetrical tree that tends to put multiple leaves out at the same height. When the tree is younger, it may look more shrub-like; however, as the tree matures and grows much taller, it becomes much more upright. |
Growth |
Slow |
ID Characteristic |
Ravenea rivularis has a distinct bark colouring and prominent leaf scars around the trunk. However, it can often be confused with Heterospathe elata. To tell them apart, look at the leaflets. On Ravenea rivularis the leaflets are regularly arranged, whereas on Heterospathe elata, the leaflets are irregularly arranged. The base of the trunk of this tree is flared out and as the tree grows taller, the trunk becomes thinner. |
Pests |
In the southern United States Ravenea rivularis can suffer from aphids, whitefly, scale, leaf spots, ganoderma root and butt rot. There is not much documentation on the pests and diseases of this tree in its natural habitat, however, there is quite a bit of documentation of pests and diseases of this tree in the United States. |
Habitat |
Ravenea rivularis is most commonly found growing alongside river banks and in lowland forests in south and central Madagascar. It is also found growing in swamps and slow moving rivers, this means that it is very tolerant of damp soils. However, when the tree is not grown in its natural habitat, it prefers constantly moist soil that is not dripping wet. |
Bark/Stem Description |
The stem of Ravenea rivularis can grow up to 22 meters tall and 35-50 centimetres in diameter. The bark is a pale grey colour with rings due to leaf scars every 4-10 centimetres. The trunk bulges at the base and then thins out as the tree grows taller. The thinnest point on the tree is right at the crown, where it will be quite a bit thinner than the rest of the tree. |
Flower/Leaf Bud Description |
When flowering, Ravenea rivularis grows a long stem, about 90 centimetres on male plants and 1.5 meters on female plants. The buds are green in colour and between 0.9 - 1.1 centimetres wide. These buds grow in groups of 5 - 7. |
Leaf Description |
The leaves of Ravenea rivularis grow to be between 2-2.5 meters long. The leaves are pinnate and twist near the top, with the leaflets all growing out of a single plane. The leaves are green on both sides and have small, tan ramenta on some parts of the undersides of the leaves. The midrib is very prominent in this plant, as are the secondary veins in the leaflets. |
Flower Description |
The male and female flowers of Ravenea rivularis grow on separate plants. The male flowers are white and can be up to 90 centimetres long. The female flowers are also white and can grow from 1-1.5 meters long. The actual flowers on the inflorescence are between 0.9 centimetres and 1.1 centimetres. |
Fruit Description |
The fruit length of Ravenea rivularis is between 90 mm and 1.3 centimetres; width would be about the same as the fruit is spherical. The fruit colour is red or reddish brown and grows in clusters. |
Colour Description |
The leaves of Ravenea rivularis are a very bright, glossy green. As the tree is an evergreen, the leaves will stay this colour throughout the year. This tree also has attractive grey bark; it is very light in colour with darker rings from leaf scars. Both the male and female flowers on this tree are a stunning white colour that hangs from the tree, breaking up the constant green from the leaves. Ravenea rivularis has an attractive red/reddish brown spherical fruit that grows in clusters, also breaking up the constant green from the leaves. |
Texture Description |
Ravenea rivularis has a textured trunk due to leaf scars. It has rings going up the trunk that are 4 - 10 centimetres apart. The leaves of this tree have a very prominent midrib on the underside of each leaf, as well as prominent veins on all the leaflets. |
Notable Specimens |
Stan Walkley’s Garden in Queensland, Australia has quite a few mature specimens on display. |
Propagation |
Ravenea rivularis can be propagated from seed, the outer fruit should be removed and the seed should be soaked in water for a short period of time. When planting, place the seed 2.5 centimetres below the surface and water daily until the seed germinates. This process can take up to 3 months. |
Ethnobotanical Uses (Disclaimer) |
In Madagascar, palm trees can be used for a variety of things, such as: weaving and thatching the leaves to make baskets and other similar items, using the trunk fibres as rope, and when a palm tree dies the larvae of weevils can be collected while it is decomposing. When tested by pharmacologists and phytochemists in Cairo, Egypt, Ravenea rivularis was found to have antioxidant and anti-inflammatory properties. These tests have not yet been put into practical use; however there is potential for an ethnobotanical use of them in the future. |