Senecio (2003)

PhotoBy Roy Kasten (January 2003)

In my succulent hunts, I have come to enjoy collecting senecios (Asteraceae). They add a lot of leaf variety and flowering to my hobby.

These succulents are closely related to the groundsel weed. The inflourescences are composed of many small flowers which scarcely have petals, just stamens and anthers. HSCSS members Steve and Joe use a monocular magnifying glass to get a closer look at the blooms – they are amazing close up. The spent blooms form tufts of silk with a seed attached at the end, which is borne off by the wind to germinate a fair distance from its parent.

There are over 80 species of Senecio in cultivation. They come primarily from central and southern Africa, Madagascar, the Canary Islands, Arabia and Mexico. There are some species in other countries, as well. Some species from Madagascar need extra warmth in winter.

Most senecios are easy to cultivate and are often favored by beginners to the hobby. The most available species include Senecio articulatus or “candle plant.” It is happy growing in almost any conditions, but too much food and/or water will result in long and tall growth. The flowers are cream-colored, and like many senecios, are not very pleasant-smelling.

Senecio rowleyanus or String of Pearls works well in a hanging basket. It rarely flowers in captivity. S. amaniensis from Tanzania has large, round, flat leaves which are white. It can grow up to 24 inches in length, and can get top-heavy and reluctant to stand without support. The inflourescence in late summer to autumn has orange flowers and smells atrocious.

S. kleinia is a tree form from the Canary Islands that can grow up to 10 feet. Another tree form is S. praecox from Mexico. It has large palmate leaves and also reaches about 10 feet. In cultivation, this plant is prone to red spider mites and needs to be treated regularly and placed outdoors for the summer.

S. stapeliiformis is very popular and easily propagated, and has distinctive purple-red stripes up the stem. The flowers are a good, strong scarlet color. S. picticualis is somewhat similar to S. articulatus but has cotton-candy pink flowers.

There are also senecios with underground tubers, including S. fulgens and S. nyikensis. They are evergreen and have glaucous leaves and bright red flowers. Also worth mentioning is the hairy-leaved S. haworthii, also available under the name Kleinia tomentosa. It has yellow flowers, but does not flower in cultivation.

Bring and show off your senecios, at the January meeting, especially if they are flowering. I will ask Steve and Joe to bring their monocular, and we can hold our noses while looking at the flowers.