Pondoland C.R.E.W. Blog: February 2016

Saturday 13 February 2016

The cool option of the Lourie Trail

With the maximum temperature predicted to reach close to 30 degrees Celsius we elected to walk in the shade of the forest from the Pont entrance of the Umtamvuna Nature Reserve.

Not many of the tree species in the forest were flowering, but we did come across some shade-loving herbs such as the delicate Asystasia varia, and in a more sunny spot, a rather interesting pale lilac (rather than the normal blue flowered form) coloured Commenlina erecta.

Asystasia varia

Commelina erecta

A spotted Oncinotis tenuiloba stem spiraling up a small tree made an interesting composition.

Oncinotis tenuiloba

We came across a population of the invasive sword fern, Nephrolepis cordifolia subsp. cordifolia, which we stopped to uproot. Two methods of crushing the fleshy tubers to prevent regeneration emerged - the finger crush and the foot crush. We hope these efforts will have destroyed this population.

Invasive fern eradication

Crushing tubers by hand

Crushing tubers underfoot

Later, when we got down near the Umtamvuna River, we saw some Duvernoia adhatodiodes and on the floodplain we came across some bright orange Crocosmia aurea.

Duvernoia adhatodiodes

Crocosmia aurea

On the way home we stopped at the roadside to collect a specimen of the emerging invasive species Desmodium tortuosum.

Desmodium tortuosum

Desmodium tortuosum - young inflorescense

Participants: Anne S, Dorothy M, Graham G, Kate G, Maggie A, Uschi T.

Sunday 7 February 2016

Checking other Eugenia species for rust

After learning last week about the rust infestations to three endemic Eugenia species, we decided to investigate the extent to which other Eugenia growing in our area might be affected.

We started off in wet conditions (yay!) at Rennies' Beach where we knew Eugenia capensis subsp. capensis grows on the first line of dunes. We found a number of these plants but fortunately, none of them appeared to show any signs of the rust we saw last week. Strangely, in one place there was a Mimusops caffra growing together with a Eugenia capensis subsp. capensis and this had several leaves with similar-looking yellow spots to the rust infestations of last week, so we collected some of these leaves.

During this search we came across a brightly-coloured sprawl of Ipomoea pes-caprae on the beach side of the first line of dunes.

Ipomoea pes-caprae

We then drove up to the Red Desert Nature Reserve where we intended to look for Eugenia albanensis and Eugenia capensis subsp. guenzii. Just before we reached the exposed yardangs we came across several bushes of Tephrosia grandiflora flowering beautifully.

Tephrosia grandiflora

As the next photo shows, the conditions remained rather moist.

Looking for rust on Eugenia albanensis (photo: Maggie Abbott)

Once again, while we did find suspicious spots on some of the the leaves of both these species, neither showed the same signs we saw last week. Once again, we took leaf specimens so we could confirm the lack of rust with the Pretoria University team.

After consulting with them and having sent representative photos of affected leaves, we were reassured that none of the Eugenia appear to have the Myrtle Rust that is affecting the species we saw last week. It seems that the spotted leaves on these Eugenia were caused by other fungi or insect galls. Interestingly, apparently the yellow spots we saw on the Mimusops leaves are a rust, but in this case, an indigenous one, so no reason for concern. Thanks to Jolanda Roux for checking these specimens.

Participants: Anne S, Dorothy M, Graham G, Kate G, Maggie A, Uschi T.