Bowiea volubilis; Climbing Green Lily, Bowiea, Climbing Potato; Knolklimop (Afrikaans); gibizila (Siswati); iguleni, igibisila, ugibisila (Zulu); umgaqana (Xhosa)
|As a young boy, this intriguing plant attracted my attention due to its large green fleshy bulbs. A family friend had a huge plant growing for years in a pot on his verandah. His servants used to break off suckers of the plant for their own medicinal use and when asked what the plant was used for, I was always told it was an intelezi – the Zulu word for a protective charm that renders evil ineffective. Mairn Hulme’s book “Wild Flowers of Natal” published in about 1954, was the first book on KwaZulu-Natal flora that I was able to get my hands on, and in it she gave clear descriptions of this plant and its uses. I quote her: “a slender almost leafless herbaceous perennial climber, arising singly from a green bulb that is almost completely exposed. Usually found in bushy krantzes.” It is found down into the eastern Cape, here in KZN, through Swaziland, Mpumalanga and into Mozambique. It inhabits the scree slopes, on ledges and at the bases of krantzes and rocky outcrops throughout the warmer parts of these regions. It grows in the leaf litter in semi-shade and has semi-succulent roots that spread widely from the parent bulb.
Plants can be propagated from division of the suckers away from the base of the parent bulb. However, I have found that the most successful way of growing this fast- growing plant is from seed. The seeds are collected from swollen green capsules that when ripe, show the black seeds within. I pick the capsules just before they split, and each capsule contains up to about 20 seeds. The seeds germinate in about a week from sowing and grow rapidly for the first month or so and then just sit for the winter. In the following spring they revive and set off with new growth. It is this leafless growth, mentioned by Mairn Hulme, that most people confuse with leaves, when in fact it is the flowering stem, and this is the main photosynthetic generator. Later in the summer, the greenish flowers that are about 10mm in diameter are produced. The capsules are ready about a month or so later in late February.
I have had plants in cultivation that have produced seed in one season from sowing the original seed. That is quick for a perennial plant, but it takes about 5 -10 years for the bulbs to get to the 100-150 mm diameter size.
For best results let the flowering stem clamber over a shrub or up some trellis-work attached to the container that this plant is growing in. The green parts like to be in fairly strong sunlight but bulbs will get sunburnt if they are not shaded for most of the day.
This is a highly prized medicinal plant that is collected by herbalists throughout its natural range. What I have noticed over the last 30 years, is that the size of bulbs being traded in the main medicinal plant markets in Durban are now virtually only one or two year-old plants, with bulb diameters of about 10-30 mm being the norm. The medicinal use described by Mairn Hulme makes interesting reading, “Gibisila. An infusion is made from the crushed bulb mixed with those from certain other plants and used to wash the body as a protection when passing through country infested by footpads or other enemies. See Intelezi. [She then in another part of her book describes in detail protective charms.] It is also used as a lotion for sore eyes, and for skin diseases.”
HOWEVER!!! I must warn readers that these bulbs or pieces of the bulb are extremely toxic if ingested. The chemicals within the bulb are heart glycosides with a digitalis-like effect on the body. Both animal and human deaths due to heart failure have been caused by this plant.