Silvermine Nature Reserve

On Tuesday, the 29^th of July, I had the opportunity to go plant collecting at Silvermine Nature Reserve. Silvermine is located on top of the peninsula range just north of Kalk Bay. On this trip, I was accompanied by Megan (student), Louise (horticulturist), Monique (horticulturist), and Deion (Monique’s glasshouse worker). Louise is a specialist on Proteaceae and Restionaceae plants and Monique is a specialist on Annuals and Herbacious plants along with Disas (orchids) and Draseras (carnivorous sundews).

From left to right: Deion, Megan, Monique, and Louise

Silvermine was a gold mine when it came to plants (no pun intended). An incredible display of fynbos diversity. Pictures cannot portray the insurmountable wildlife in the area. One must visit the reserve to really develop an appreciation for the landscape above on top of these mountains. Before we arrived at Silvermine, I did not fully understand the hype about Leucadendrons. Leucadendrons which have cones, rather than showy bracts or floral features like leucospermums and proteas. When we arrived, the first thing that caught my eye was how brightly yellow the hills were painted. Up close, I realized that this yellow comes from the mass population of Leucadendron laureolum.

As you venture further down the trails, there are swafts of pink Ericas painting the hills as well. 

This Erica is not pink, but I find the green flowers to be amazing when you get close up to them.

Mimetes fimbriifolius with bright red flowers and growing into big dense bushes standing at 10 feet tall. In the garden, the Mimetes grow half the size with a duller color.

In San Luis Obispo, one of the local favorites is the Psoralea pinnata, a South African shrub which produces a delightful grape jolly rancher fragrance. In this reserve, these shrubs appear all over. I can’t imagine how lovely the area smells in near the beginning of summer.

And not to mention the King of the Proteas, Protea cyanthoides growing in the wild!

Some of these plants grew as tall as 6 feet with multiple flower heads. But look at the size of those flowers!

The combination of these plants, the natural land formation, and the sound of running water from the streams creates a surreal environment for any nature lover to adventure.

This trip was stemmed by Megan’s desire to add Saltera sarcocolla into her section of the Protea garden. Saltera sarcocolla is a member of the Penaeaceae family and has these cute little pink flowers, which are located at the tip of long stems arising from the crown. Members of this family only appear in South Africa and appear evergreen with closely ranked, alternating opposite leaves which give it a distinguishable look. Unfortunately, the stems arise from a woody underground rootstock and the only way to successfully propagate these plants is with some of the rootstock. It was extremely difficult to find juvenile stems arising out of the ground to collect. We were probably a month too late on collecting these.

One of the highlights of this trip was finding these!

These are Droseras, commonly known as a Sundews! These grow in soils with good drainage and near moist areas. Specifically, we found these on stream banks, vernal pools, and along the trails where run-off water would build up. Check out this specimen where the plant was literally growing in a patch of moss!

Impressive right? That’s not even the cool part, these plants are carnivorous! The leaves have marginal hairs and sticky droplets which looks like morning dew. This mucus-like substance on the leaves are used for capturing insects. The plant secretes an enzyme used to break down the exoskeleton of the insect which then provides a secondary source of nitrogen for the plants. I had never seen carnivorous plants in the wild, so as you can imagine, this was quite the treasure for a developing horticulturist. 

To collect these samples, we focused on collecting young seedlings. Sundews possess a long taproot which they rely on for their survival. Extracting juveniles is much easier to successfully remove the whole taproot and has less of an impact on the population. There is a much higher chance that a juvenile will not survive to reproduce than a fully developed plant.

Here is another treasure we came across on the trails.

These are Disas, the local orchid. These specifically are Disa uniflora and Disa racemosa. Other Disas possess multiple flowers and multiple colors. These orchids are geophytes and grow from tuberous roots, rather than the typical epiphytic orchid that survives on organic matter.

We also viewed a number of little bulbs and restios which caught our attention as well.

At the end of our trek, we collected retired cones of the beautiful Protea lepidocarpidendron, a white colored protea flower with a black tip.

This unique Protea is not represented at Kirstenbosch and was on Louise’s list of plants to collect. Each year, every stem produces a cone at the tip. When the new year’s growth starts to form, it grows around the old cones. What we are looking for are the old cones produced from the previous year, as seen below. It takes about a year for the seeds to develop in these old cones. When they are ready, only about 5% of the yield is viable. This is a strategy Proteas have adapted to produce higher chances of seed survival. By creating sterile seeds, they use less energy and create less odds for predators to consume the next generation.

When we picked the cones, we would look for little holes on the bracts to verify any insect activity. If a beetle bore its way inside, chances are much higher that it has extinguished the valuable seeds or we will be spreading the pest; these insect ridden cones were left in the wild.

Below is a dissection of the Protea floret.

When we arrived back, Louise placed the cones in a drying oven for 3-4 days. When the cones were dried, the seeds were then extracted and planted in a bed of well-draining substrate (mostly sand and bark), with a light top cover.