Know Your Fynbos | Let’s talk Leucadendrons

Know Your Fynbos | Let’s talk Leucadendrons

Leucadendron: a rather serious-sounding title for this lively fynbos shrub that we see dotted across the mountain in a rainbow of different hues. Its common name ‘conebush’ sounds quite ordinary too, but species like silver tree, spinning top, golden sunshine and silky-ruff begin to paint a more accurate picture of how diverse and superb this plant can be.

What to look out for:

It’s not surprising that Leucadendrons belong to the Protea (Proteaceae) family. Their overall appearance and the way in which their leaves are arranged make them look much like sugar-bush proteas at a glance, but on closer inspection you’ll find they are missing that goblet-shaped Protea head we know so well.

So which is the Leucadendron then? One very striking species you may have come across in Kirstenbosch or on Table Mountain is the Silver Tree (Leucadendron argenteum); the tall, emerald-green, leafy tree, known for the silvery-white sheen it adopts when tiny hairs on its leaves catch the sunlight (1). Another one that may ring bells for mountain explorers is the Golden conebush (Leucadendron laureolum), which turns Cape mountainsides bright yellow in winter. What we see as a mass of yellow ‘flowers’ erupting on the slope is really the plant’s bright, yellow-green involucral (modified) leaves. These conceal the flower-heads, which themselves are packed with numerous tiny flowers (2).

We could go on and on with the list of familiar favourites, as Southern Africa has 82 Leucadendron species, ranging from bright yellow to deep crimson. Instead, here are one or two simple things to look out for:

• Cone: The name ‘conebush’ came about because the female flower heads produce woody cones from which the fruits are borne. After flowering, the flower-heads continue to grow until they form cones, which eventually become hard and woody. In some varieties, the cones start out rosy-pink, resembling rosebuds (3).
• Leaves: These come in a rainbow of colours, but most are oblong, ending in a blunt, recurved point, with a durable, waxy feel (4).
• Stem: Aside from the Silver Tree (which is classified as a tree and not a shrub at 7-10m tall), Leucadendron shrubs usually range from 1-3m tall.

For some useful visual clues, have a look at the Leucadendron species list here.

What you might not know:

1. The name ‘Leucadendron’ comes from the Greek word ‘leukos’, meaning white and ‘dendron’ meaning tree. It was named after perhaps the most conspicuous of the Leucadendron species, the Silver Tree (Leucadendron argenteum) (5).
2. Leucadendrons have become a popular choice for indigenous gardens, owing to their colourful bracts (modified leaves), water-wise properties and long-lasting vase life. They are now cultivated as a range of commercial hybrids like ‘Safari Sunset’, ‘Inca Gold’, ‘Asteroid’, ‘Chameleon’ and plenty of others (6).
3. The Silver Tree is rare and endangered, facing an extremely high risk of extinction in the wild due to loss of habitat from urbanisation and agriculture (7).
4. The Leucadendron is dioecious, meaning that it has separate male and female plants. By contrast, most plants are hermaphroditic which means both male and female organs are contained on one plant, and on one flower (8).

 

References:

1, 7. Leucadendron argenteum | Plantz Africa [Internet]. Pza.sanbi.org. 2017 [cited 8 June 2017]. Available from: http://pza.sanbi.org/leucadendron-argenteum

2, 4, 5. Leucadendron laureolum | Plantz Africa [Internet]. Pza.sanbi.org. 2017 [cited 8 June 2017]. Available from: http://pza.sanbi.org/leucadendron-laureolum

3. Leucadendron laxum | Plantz Africa [Internet]. Pza.sanbi.org. 2017 [cited 8 June 2017]. Available from: http://pza.sanbi.org/leucadendron-laxum
4. Leucadendron [Internet]. En.wikipedia.org. 2017 [cited 8 June 2017]. Available from: https://en.wikipedia.org/wiki/Leucadendron
5. Dioecy [Internet]. Proteaatlas.org.za. 2017 [cited 8 June 2017]. Available from: http://www.proteaatlas.org.za/dioecy.htm

Photo credit: Andrew Massyn