Vanilla roscheri

Family: Orchidaceae

The flower of Vanilla roscheri photo taken by Roddy JC Ward

A very attractive orchid that has a widespread range in eastern tropical Africa, from Kenya, Tanzania and Mozambique with one officially recorded record from South Africa. The specimens found in South Africa were found on the shores of Lake Sibaya by Mark Ward in 1983 where herbarium specimens were collected by him on the 05/02/1983 and again on 01/07/1983 which were submitted to the Herbarium at the Royal Botanic Gardens by his father Roddy Ward. I am very fortunate to have been given a live piece of the original plant collected.

Status in South Africa

Near Threatened* D2 assessed on the 02.09.2005 by L. von Staden and J.E. Victor

Known from one location in South Africa. Potentially threatened by subsistence agriculture, expanding informal settlements and alien plant invasion. The national assessment is downgraded from VU to NT as other subpopulations just across the border in Mozambique could serve as sources of propagules to South African locations.

Note:

This species may be conspecific with Vanilla phalaenopsis Reichenbach f. from the Seychelles and with Vanilla madagascariensis Rolfe from Madagascar, if so, Vanilla phalaenopsis would be the correct name.

Description

Vanilla roscheri is a leafless, terete liana-like climber with green succulent stems up to c. 1.5 cm in diameter with short thin wiry attachment roots at the nodes and at intervals along the length of the stem different feeding roots are send down to the ground where they take up water and nutrient in the leaf litter and soil to sustain the plant. These orchids are not epiphytes but terrestrial orchids that grow in the ground and along the forest floor then climb up into the canopy to get more light to flower and must therefore be planted into sufficiently large pots or in the ground if grown outdoors to do well.

Here one can see the huge amounts of roots sent down by a plant growing in the forest canopy to sustain growth.

Small brownish vestigial leaves up to 3 cm long are present at the nodes on new growth which fall off after a few months.

Here the vestigial leaves are clearly seen on Vanilla roscheri grown in my lounge

A very distinguishing feature of this species are two shallow channels on each side running the length of the vine between the internodes which are up to 15 cm long.

Here one can see one of the two shallow channels on each side the vine of Vanilla roscheri as well as one of the feeder roots and the thin roots used as to attach themselves when climbing into the canopy.

The inflorescence is many-flowered, up to 30 cm long, terminal or at the nodes. Flowers are large and showy, up to 15 cm in diameter, white, more or less flushed with pink, strongly and sweetly scented. Lip funnel-shaped, often salmon-pink or yellowish in the throat. Capsule up to 17.5 cm long

Photo of flower of Vanilla roscheri taken by Roddy JC Ward

Habitat

Vanilla roscheri are found growing where it is hot and humid near to the coast in mangrove forest, evergreen scrub, coastal bush and forest, and in grassy fields rocks and scattered trees at elevations in South Africa 1-100 m, elsewhere at elevations of 0 up to 1050 meters

Cultivation

Vanilla roscheri which is easy to grow likes to grow at warm to hot temperatures with high humidity with the lower part of the plant and the roots in shade, the top of the plant in partial shade to full sun for them to flower.

Seed pods of Vanilla roscheri growing on Erythrina latissima in full sun at Lake Sibaya Photo taken by Roddy JC Ward

Vanilla roscheri plants require a large pot filled with a very loose well drained open growing medium with lots of space for climbing. I used to grow mine in very coarse sieved well drained leaf mould containing many sticks and partially decomposed leaves to which can be added some crushed egg or snail shells. I have however found that they grow just as well or better in a very open growing medium of fine medium and course silica sand with a little peat or coconut peat added. It is essential to add good drainage and airholes on the sides at the base of the pot or to place the pot on feet. The plants must be allowed to dry out somewhat before watering. Reduce the watering in the cooler months. They need good air movement and respond well to misting. They respond well to a regular addition of a very weak solution of liquid fertilizers and or a littler slow release fertilizer such as Multicote™ controlled release fertilizer . Flush out the pot well with clean water from time to time to avoid salt build up.

Vanilla roscheri growing indoors

I feed my orchid plants with soluble inorganic fertilizer used in hydroponics for flower and fruit growth to which I add both humic and fulvic acid, Seagro which is an Organic Plant Food, a nutritious fish emulsion, Marinure® which is a unique biostimulant brown seaweed, Ascophyllum nodosum and Nitrosol, which gives excellent results. I occasionally water my plants with plant growth stimulants derived from sea weed.

The Royal Botanic Gardens at Kew
Herbarium Catalogue
Family:	Orchidaceae
Current Name:	Vanilla roscheri Rchb. f.
Collector:	Ward, C.J.; Ward, M.C.	Plant Parts:	Flowers/inflorescence; Fruit
Collector no:	59
Collection Date:	05/02/1983
Country:	South Africa	Habitat:	Light shade; sand termite mound. Dry woodland-forest, mainly just within margin. Frequency; Locally common.
Location:	KwaZulu-Natal Ingwavuma Sibaya lake south west	Plant Description:	Shallowly rooted in litter on sand or pseudo-epiphytic.
Lat and Long:	27 21 S , 32 36 E
General Comments:	Sheet 1. Duplicate Ex Herbarium: University of Durban-Westville, Natal, South Africa.