Pollination strategies of Plants and Birds

This month’s talk in the Fernkloof Hall was given by Prof Johann du Preez who discussed the pollination strategies of both plants and their animal pollinators.

As birds are major plant pollinators, we invited members of the local bird clubs to join us.

“Nothing on earth is permanent” says Johann at the start of his brilliant overview of life on earth from its emergence to the present. Since the early development of flowering plants about 130 million years ago plants have changed considerably.

Evolution of the sex organs has been most spectacular. Protection from dessication and predation was important, but the changes driven by the necessity for pollination to ensure survival of the species had to co-evolve with the animal pollinators.

Johann asked what might pollinate the world’s largest single flower plant, Rafflesia on the Borneo forest floor? No sunshine penetrates there but flies are attracted to dead animals, Rafflesia has developed a similar smell, to ensure that flies are its pollinators.

The sausage tree (Kigelia africana) of the Kruger National Park opens its blood red flowers at night which attract bats.

Many plants develop long tubular flowers which can only be pollinated by the long curved bills of sunbirds and sugarbirds. Although specialisation comes at a cost there are advantages, floral parts can be reduced, and the nectar is protected deep inside the flower. Trouble comes when a particular specialised bird species becomes rare, then pollination may become impossible and the plant faces extinction.

Johann closed his fascinating talk with illustrations of a sunbird walking up the strong blue stigma of Strelitzia reginae to reach the nectar, and in the process exposes the pollen anthers by its own weight, thus covering its feet with pollen. And the story of the Australian thynnid wasp which, after attempting to mate with the spring-loaded lip of the hammer orchid, flies up, is thrown forward and hits its head on the pollinia had the audience in fits of laughter!

Submitted by Deirdre

Stigma of Strelitzia reginae

Stigma of Strelitzia reginae

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De Bos Wetland trail. Wednesday 25 April 2016

A large group of Wednesday botanical enthusiasts set off on Wednesday on the new trail that Frank Woodvine has laid out on De Bos farm, next to De Bos dam on the Karwyderskraal road, in the Hemel & Aarde Valley. The trail will be self-guided with arrows indicating the way and numbered posts with a descriptive guide explaining features of interest at each post. The trail starts at De Bos’s new restaurant and wine tasting centre, passes though wetlands with rich bird and plant life as well as vineyards and orchards and reaches the lowers slopes of the Babylonstoring mountain range. Here the fynbos was spectacular. Protea lacticolor was in full bloom. We were thrilled to find Amphithalea tomentosa and the rare Audouinia capitata both in bud which warrants another visit soon when the pretty Erica peziza will be in flower too. There was a beautiful Aspalathus we need to identify and more.

The rail is 7.3 km long but shorter versions are possible. Definitely worth exploring.

Submitted by Di Marais

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A Very Small Insect

Wees verseker dat in die Fynbos daar altyd iets sal wees om ons botaniese entoesiaste opnuut te beindruk!

Onlangs was ons soos gewoonlik besig om voorbeelde van Fynbos wat op die oomblik blom, te versamel om in die Besoekersentrum te vertoon.  My aandag word gevestig op ‘n onopsigtelike lid van die Asteraceae familie, die Seriphium incanum, se ongewone baie klein blommetjie, wat terloops glad nie na ‘n aster lyk nie.  Natuurlik word die kamera vir ‘n foto uitgehaal, en tot ons verbasing is daar ‘n piepklein goggatjie perfek gekamoefleer daarop.

IMG_4225a

Dr Vic Hamilton-Attwell was so vriendelik om die foto aan ‘n entomoloog, Dr Ian Miller, te stuur, wat van mening is dat dit in die orde Hemiptera: Heteroptera: Fam. Miridae: Subfam. Mirinae val.   Nou wat interessant is, is dat Pameridea  wat ook baie klein is en op Roridula voorkom, ook in die familie val.    Hy is nogal geinteresseerd, daar is min kennis van die familie en subfamilie.    Volgens Vic gaan hulle die identifikasie verder navors.

Submitted by Fran Jordaan

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More Images from Gilly

This gallery contains 7 photos.

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Nerine sarniensis

A large Botanical group visited Vogelgat yesterday on a quest to see the flowering Nerine sarniensis (Guersnsey lily).

ine

Colour variations include red, rarely pink or white flowers with erect stamens.  Found growing on rocky south and north-west facing slopes in the SW Cape.

Family: Amaryllidaceae

Common names: Guernsey lily, red nerine, berglelie

Nerine sarniensis, commonly known as Guernsey lily or Jersey lily,[2] is a species of flowering plant in the family Amaryllidaceae. It is the type species of the Nerine genus. It is widely cultivated in the temperate world and is particularly associated with the island of Guernsey, as reflected in both its Latin and common names (sarniensis means “from Guernsey”),[3] though it does not originate there, nor is it a true lily (it is more closely related to Amaryllis and Sternbergia). It is native to the Northern and Western Cape Provinces of South Africa, There are 4 fynbos species of Nerine.

Trivia

Derivation of name and historical aspects

This beautiful Nerine has a colourful history. The often-told but unlikely tale of how boxes of bulbs of South Africa’s most famous Nerine, consigned for Holland, were cast away from a sinking ship in 1659 and took root and flourished on the shores of Guernsey in the Channel Islands, has become something of a botanical legend. Whatever the truth is regarding the arrival of Nerine sarniensis on Guernsey, its bulbs have been cultivated there for more than three centuries, and continue to be grown there for their cut flowers.

The cleric and amaryllid expert, Rev. William Herbert, established the genus Nerine in 1820. It is unclear whether he named it for Nerine, the Greek mythological sea nymph and daughter of sea God Nereis and Doris, or for Nereide, the daughter of Nereus, son of Oceanus. The specific epithet sarniensis refers to the Island of Sarnia, the Roman name for Guernsey, where Nerine sarniensis was at one time thought to have occurred naturally.

Submitted by Gilly

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Dot’s Dash 2018

This gallery contains 10 photos.

Originally posted on roncorylus:
Nine Hurriers had the pleasure of walking Dot’s Dash this morning.  It was perfect walking weather apart from the rather stiff breeze, but there were plenty of places where we were in the lee of the…

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Identification please!

On this morning’s BotSoc walk to study the various Lobelia in flower, a pretty caterpillar was photographed by Derek Silberblatt. Can anybody say what it is?

He also submitted a picture of a nest in an Erica bush that he thinks may be that of a Grassbird.

Posted in Insects, Plants, Walks | 2 Comments