Knersvlakte Section in the Conservatory
A view of the Knersvlakte section with Aloe dichtoma and Tylecodon paniculatus in the background. Note the quartz gravel.
The Knersvlakte region is situated in the north-west corner of the Western Cape Province. It consists of a hilly terrain covered with quartz gravel. The vegetation is succulent karoo and dominated by leaf succulents (Mesembryanthemaceae, Crassulaceae) and shrubs spread amongst them. Many succulents are confined to the white quartz gravel, which reflects the sunlight, and is not as hot as the darker rocks and soil. Many of the succulents here are usually dwarf and compact; an ideal proportion to absorb thermal heat for the short cool winter growing season when rain occurs. The climate is semi-arid with long dry summers. The Knersvlakte represents one of the richest succulent plant diversity centers. This is also the southern most distribution of the quiver tree (Aloe dichotoma). The quartz gravel and rocks in this display were kindly donated by Buys Wiese from the farm Quaggaskop.

The dominant vegetation displayed is succulent karoo, with members of the Mesembryanthemaceae prominent. The bababoudjies (Argyroderma) are prominent dwarf compact plants resembling pebbles and have been planted throughout on the white quartz. Their silver-green or gray leaves reflect the sunlight. Argyroderma (argyros = silver and derma = skin) have attractive purple or yellow flowers during the autum and winter. Their fruiting capsules like all other members of the Mesembryanthemaceae are hygrochastical, only opening with moisture. The velocity of raindrops on the wet capsule roofs disperses the seed by water pressure, almost like a water pistol. When the capsule dries out the lids close, protecting the seed. The seed are thus only released during the rainy season.

The Conophytum calculus looks like a cluster of gray marbles. This remarkable plant becomes dormant during the long dry summers. Yellow flowers appear in autumn. Other dwarf mesembs include Oophytum nanus, O. oviforme and Diplosoma insignis. The stonecrop family (Crassulaceae) is also well represented here with members such as the spekboom (Tylecodon paniculatus), the shrubby Crassula macowanii and dwarf Crassula columnaris.

Aloe falcata in Knersvlakte bedThe aloe family is also represented here (Aloaceae). The sickle aloe (Aloe falcata) has rough sickle-shaped leaves. Its panicle of red tubular flowers is produced in midsummer. The ox-tongue (Gasteria pillansii) has mottled leaves in opposite rows. Its elongated racemes are produced during summer. The koekemakranka (Gethyllis namaquensis) is a bulbous plant, which becomes deciduous in summer. It has a snake like stem emerging from the ground with protruding linear leaves. The sweet smelling white to mauve flowers appear during December, followed by fragrant edible fruit in autumn. The tall quiver trees reach their southern limit here. They are slow growing and flower during winter. The San tribes (Bushman) used the tree stems as quivers. Their racemes of yellow tubular flowers are pollinated by sunbirds.
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