* Guest column by Theo Heijnsdijk
The year 1778 is an important one for Crassula lovers. In that year, an article appeared in the Swedish periodical with the wonderful name ‘Nova Acta Physico-Medica Academiae Caesareae Leopoldino-Carolinae Naturae Curiosum’ in which physician-botanist Carl Peter Thunberg (also from Sweden) briefly described no less than 28 new South African species of this genus. Most of these have become well-known among fanciers. Just think of Crassula alpestris, C. barbata, C. capitella, C. columnaris, C. corallina, C. hemisphaerica, C. tecta, C. tomentosa, and the subject of this article: C. pyramidalis.
At the back of Thunberg’s book is a plate depicting 2 of the new species, C. alpestris and C. pyramidalis (see fig. 1).
fig. 1
In later years, of course, many more images of C. pyramidalis appeared. Particularly beautiful is the coloured plate published in 1899 in Curtis’s Botanical Magazine (fig. 2). Here we see a thicker shape than Thunberg’s plant has.
C. pyramidalis is closely related to C. columnaris (discussed earlier in this series) and to C. barklyi. All three of them are highly succulent species whose leaves are so tightly packed together that the stem is totally invisible. In C. pyramidalis, the leaves are grouped very regularly. At the top of a stem, this results in a particularly beautiful view (fig. 3).
In nature, the plants can take on a beautiful purple-red color (See figure 4). Coby Keizer took this picture in November 2008 about 60 km north of Matjiesfontein (Western Cape) along the road to Sutherland.
Not visible in photos are the hairs in the leaf axils. They allow the plant to absorb water. In the Dutch picture album of the Verkade Company this is described by the author, A. J. van Laren, as follows:
‟Remarkable in some of these Crassulas is the ability to absorb water by means of hairs on the leaves, such as the marginal hairs of C. barbata; in C. columnaris and C. pyramidalis there are such water-absorbing hairs at the base of the leaves, thus at the trunk. The effectiveness of these hairs is rather significant! To give an example, a leaf of C. barbata can absorb more water in one night, as a result of dew, than it loses in a week by transpiration. The placement of the leaves in C. pyramidalis is such that water flowing down the plant penetrates into the spaces between the leaves, from where it is channeled to the base and absorbed by the hairs present there. When drought sets in, the leaf margins are so close together that the water-absorbing hairs at the base of the leaves are completely closed off from the outside air and therefore cannot lose water.
I suspect that van Laren derived the above information from the book which the German chemist/pharmacist/botanist Rudolph Marloth (1855 -1931) wrote under the title ‘Das Kapland, insonderheit das Reich der Kapflora, das Waldgebiet und die Karroo’. This book with over 550 pages in 1908 as part 3, volume 2 of a whole series under the title ‘Wissenschaftliche Ergebnisse der Deutschen Tiefsee-expedition auf dem Dampfer “VaIdivia” 1898-1899’. The Valdivia was a steamer commissioned by the German government to undertake a deep-sea expedition in the Atlantic and Indian Oceans from August 1898 to May 1899. The report under the title mentioned above included 24 volumes, the first of which appeared in 1902 and the last in 1940. Marloth, who lived and worked in South Africa from the age of 28 until his death, did not participate in the expedition but became involved by the botanist Wilhelm Schimper who disembarked on the return trip to Cape Town to continue with botanical fieldwork. The concept of deep-sea was apparently understood very broadly. When Schimper died in 1901, Marloth was asked to complete the volume about South Africa.
In his book, Marloth reports on experiments with various Crassula species. He took 2 specimens of C. pyramidalis of which he wrapped the roots in tin foil so that they were closed off from the open air. He put the plants outside for a night. One covered with a piece of cardboard, the other one unprotected. The covered specimen lost a bit of weight (0.6%), whereas the unprotected specimen exposed to the dew increased in weight by 5.1%. Marloth concluded that the plant can absorb 5.7% of its body weight from dew. Of course, that does not prove at all that this is caused by those leaf axil hairs, but it is still a nice fact. According to Marloth, C. columnaris also has such hairs in the leaf axils. In his experiment, this species was found to experience 6.3% weight gain due to the dew. For C. barbata, the increase was 5.2%.
In addition to the position of the leaves, C. pyramidalis, C. columnaris and C. barklyi also correspond in the terminal, almost spherical inflorescence without visible flower stem (fig. 5) so that it seems as if a globule of flowers is crammed into the plant from above. The visual disadvantage is that the dried plug remains in place for a long time after flowering.
C. pyramidalis tends to allow all stem ends to bloom at once. A beautiful sight, but also the harbinger of a rapidly approaching death. This happened to me, for example, with the plant in fig. 6 that I bought at an open day at the Ubink nursery.
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fig. 6 The photo was taken 3 months after the purchase. The stems were nicely thickened and coloured slightly red by the sun. At the end of February 2012 I saw that the formation of buds had started (fig. 7). 
fig. 7 On April 1, the first flowers were open and on April 9, all stems were in bloom (fig. 8). The flowering lasts for many weeks, but the flowers gradually turn brown, after which the same thing happens to the stems themselves and then the plant is done for.
fig. 8 Thunberg found C. pyramidalis at the thermal springs on the Olifants River (Cape Province). Later, the species was found in many other places in the Cape Province (Little Karoo, Great Karoo, Namaqualand). The species is widespread in other words.. We can also come across the plant in literature under one of the following names: Crassula quadrangula, Tetraphyle pyramidalis, Tetraphyle quadrangula, Tetraphyle pyramidalis var. quadrangula, Purgosea pyramidalis, Crassula archeri and Crassula cylindrica.
In his 1778 article Thunberg wrote that C. pyramidalis resembles C. muscosa, but is distinguished by the thicker stems and the terminal inflorescence. C. muscosa is the valid name for the plant that probably most of us know as C. lycopodioides, the well-known shoelace plant. In this species, the inconspicuous and (to my mind) unpleasantly smelling flowers appear everywhere along the stems between the tiny leaves (fig. 9). Muscosa, by the way, means: moss-like, referring to the collection of thin stems. Lycopodioides means: resembling wolf’s claw (Lycopodium).
Over the years, a number of hybrids of C. pyramidalis have become available. Without a doubt the best known is ‘Buddha’s Temple’, a hybrid with C.perfoliata var. falcata. A photo of this plant in side view was already shown in the article in this series about the latter. In fig. 10 this plant is shown in top view.
We also know ‘Giant’s Watch Chain’ (C. muscosa x pyramidalis), ‘Starburst’ (C. ausensis x pyramidalis), and the multihybrides ‘Star Child’ (C. deceptor x ‘Starbust’) and ‘Tinkerbell’ (C. ausensis x ‘Springtime’) x pyramidalis) in which ‘Sprintime’ in its turn is a cross between C. perfoliata var. falcata with (probably) C. rupestris. A hybrid of no less than 4 species. It will probably make your head spin in the meantime.
A hybrid that also deserves a place here is C. ‘Extagnol’ which we also come across under the name C. ‘Estagnol’. This plant stands out because of the spiraling leaf position. In close-up (fig. 11) it reminds one somewhat of Aloe polyphylla .
But remember that the diameter of this plant is only 10 mm. Its origin is not clear, but in the literature it is stated that it is a cross between C. pyramidalis and C. perfoliata var. perfoliata. I think the leaf shape is more indicative of C. alpestris, but that is only a random guess of course.
In cultivating C. pyramidalis and all these hybrids, we must bear in mind the highly succulent character of the plants. That is to say: a mineral soil, a sunny location, careful with water and little to no fertilizer.
Literature
Heijnsdijk, T. (2013). Crassula perfoliata var. falcata, Succulenta 92 (1): 3.
Heijnsdijk, T. (2013). Crassula barklyi, Succulenta 92 (4): 178.
Hooker, J. D. (1899). Curtis’s Botanical Magazine 125, tab 7665.
Laren, van, A,J. (1932). Succulents, Verkade’s factories N.V., Zaandam.
Marloth, R. (1908). Das Kapland, Wissenschaftliche Ergebnisse der Deutschen Tiefsee-expedition auf dem Dampfer “VaIdivia” 1898-1899, bd.2, t.3.
Thunberg, C.P. (1778). Nova acta physico-medica Academiae Caesareae Leopoldino-Carolinae Naturae Curiosorum, t6: 328-341
Images:
Fig. 1 The first published image of C. pyramidalis (Thunberg, 1778)
Fig. 2 A part of the image in Curtis’s botanical from 1899
Fig. 3 A young side shoot
Fig. 4 C. pyramidalis approx. 60 km north of Matjiesfontein along the road to Sutherland. (photo Coby Keizer)
Fig. 5 The almost spherical inflorescence of C. pyramidalis.
Fig. 6 C. pyramidalis in a 5 cm pot
Fig. 7 Button formation at the plant of fig. 5 C. pyramidalis
Fig. 8 The same plant: all shoots bloom at the same time
Fig. 9 Crassula muscosa (lycopodioides) in bloom
Fig. 10 Crassula ‘Buddha’s Temple’ (C. perfoliata var. falcata x pyramidalis)
Fig.11 Crassula ‘Extagnol’ (possibly a hybrid of C. pyramidalis and C. perfoliata var.perfoliata)
Originally published in Succulenta 93 (3) 2014. Translated from Dutch by Frans Noltee.