Cotyledon orbiculata
C. orbiculata var. orbiculata along the Namaqua coast, South Africa
Cotyledon orbiculata is - together with Orbea variegata - the oldest recorded succulent from South Africa. A drawing by Dr Justus Heurnius from April 1624 shows a plant from Table mountain. Another drawing of the species appeared in the Monickx atlasses in 1701.
The genus Cotyledon was offically instated by Linneaus in 1753 with C. orbiculata as the only species.
Cotyledon orbiculata is the most widespread species in SA with lots of varieties. It is a plant of medium stature with branches decumbent to erect. The leaves are usually of a blueish colour, succulent, flat or rounded or even finger-like. The beautiful coloured flowers make it a well known garden plant.
It may be confused with C. barbeyi, but comparing the flower structure will remove all doubt.
C. orbiculata Namaqualand, SA. a plant with flat leaves
Photo © Joeyi Santore on inaturalist.org
C. orbiculata cylindrical leaf form at Buitenstekloof, SA.
Plant shape
C. orbiculata stems are erect or decumbent and being supported by surrounding bushes. Most leaves are of a blue colour, but they may be green or in some desert varieties of a dark grey-brown colour. Some have a very pretty red upper edge like a pair of lips.
It can reach a height of 1.5m or can stay quite low (var. spuria). However there are several forms that look different and are smaller. The leaves are opposite except in the var. flanaganii where they are positioned in whirls of 3.
The leaves can have many shapes: some are oval and flat, others cylindrical rounded and some even almost ball shaped.
C. orbiculata var oophyla grown at Selecta Succulent, Barrydale, SA.
C. orbiculata Namaqualand, SA. flowers
Photo © Joeyi Santore on inaturalist.org
Flowers
The inflorescence is 20-100cm long and ends in a 3 to 5 branched thyrse. The peduncle is about 3-4cm long.
The flowers vary from yellow over orange to bright red. A flower can be between 10 and 40mm long. The corolla tube is longer than the lobes
The calyx lobes are triangular, 3-6mm long, grey/red/green. The corollla tube is usually longer than the lobes. The lobes are recurved. The stamens are exerted and coloured.
Variability
C. orbiculata is very variable, has many cultivars, and has 5 official varieties described in the "Flora of Southern Africa" by Tölken. EVJ and Daryl Koutnik maintain these varieties in their book "Cotyledon and Tylecodon".
However for some varieties and forms I find it rather difficult to distinguish the types. Since the publication of that book, some varieties have been unofficially named.
What always surprises me is that different forms/varieties can grow on the same spot without any sign of intermixing.
C. orbiculata var. orbiculata at Hermanus, SA. Photo © worldtraveller27 on inaturalist.org .
C. orbiculata var. orbiculata
If other varieties are described there must be a type variety with the name of the species. It is also the most common occurring plant.
In this variety the corolla tube is not bulging in the middle.
C. orbiculata var. flanaganii? Photo © randomharvest.co.za
C. orbiculata var. flanaganii
This variety was described by Toelken in Bothalia in 1979. EVJ maintains it from plants in Valley Bushveld in the lower Key river valley. From the illustrations in the book it has long elongated cylindrical leaves with a sharp dark tip. These leaves are positioned in wirls of three on the stem.The flower seems not to differ from the type.
I could not find any reliable photo from the same region which looks like this, only commercially grown plants under that name.
C. orbiculata var. dactylopsis at Bloemfontein Photo © Alexander de Gouveya on inaturalist.org
C. orbiculata var. dactylopsis
This variety was also described by Toelken in Bothalia in 1979. It grows mainly in the Freestate. It also has 'fingerlike' leaves who keep to the ground.
The corolla tube is much shorter than the type and yellow with red spots.
C. orbiculata var. spuria at Buitenstekloof showing the very large leaves (ruler 20cm)
C. orbiculata var. spuria
The var. spuria is distinguished by its very large bluish leaves who stay low while the inflorescence is very long, up to 1m high.
It is found mainly in the winter rainfall area in the Western Cape in low scrub.
C. orbiculata var. oblonga flower showing the bulge in the middle.
C. orbiculata var. oblonga
The var. oblonga is recognized by the inflated middle part of the corolla tube. It is also a low staying plant with inflorescences. The flowers are rather large (4cm) and usually ornge coloured
It is commonly found in eastern parts of South Africa amongst dense thicket and grassy savanas.
C. orbiculata var. oophyla near Alexanderbaai .
Photo © Carl Frederick on inaturalist.org
C. orbiculata var. oophyla
This is not an officially described variety by my knowledge, but the name is used frequently to describe this very compact form from the Richtersveld. It has almost spherical leaves which are very darkly coloured.
Where
C. orbiculata occurs throughout South Africa and into Swaziland and Namibia. One can also find it in many gardens in warm climates all over the world: Spain, Mexico, California, ...
More pics
C. orbiculata var. orbiculata, Namaqualand coast. A very pretty form with prominent 'hot lips'.
C. orbiculata var. oblonga 'takbok'
Photo © Jacquie Koutsoudis