This most individual of cereoid cacti was first described as Cereus candelaris by Franz Meyen (a Prussian physician and botanist who visited Peru and Bolivia in 1831) in Allg Gartenz. 1:211 (1833). The specific name aptly describes the unusual shape of the plant with its single upright, spiny trunk crowned with a head of ascending or drooping branches which are almost spineless. In Volume II of The Cactaceae (1920), Britton and Rose erected their new genus Browningia for this one species, naming it in honour of W E. Browning, a former director of the Instituto Ingles at Santiago, Chile.
When the plants are immature they consist of a very spiny unbranched column with spines up to 15cm long, unless damaged, when branching can occur (Fig. 1). They retain this form until they reach a height of 2 to 3 metres when the spines on the new growth diminish or almost disappear and the plant begins to branch (Fig.4). Only these nearly spineless branches are capable of producing the white nocturnal flowers which are followed by fruits with unusual, thin, fleshy scales. Flowers are never produced from the spiny trunk; they can appear on young arms, but only a few at a time. They are up to 12cm long and, although nocturnal, are said to have no perfume, so I find it difficult to speculate about what the pollinator might be. The total height can eventually reach 6 metres in favourable locations but usually it is much less. Even on fully mature specimens new spines continue to grow on the woody trunk, which consequently becomes ever more spiny, presumably as protection against predation.
The habitat range of this species is extensive, from near Lima in the north (Fig.2) to at least as far south as the valley of Chusmisa in Chile, some 1,300km away. They occur between about 2,000 and 2,800m in the dry valleys on the west of the Andes, the precise altitude depending on local conditions. This is approximately the lower limit to which the summer rains penetrate from the east, although sometimes many years can pass without my rain filling on these drought- adapted plants. For some reason, perhaps local climatic conditions, they do not occur in every valley in this distribution range. Individuals never grow in dense stands, and are normally seen as isolated specimens growing some distance apart. They appear to favour the lower slopes of steep sided valleys or the bottoms of main valleys where water will occasionally run, but they are also often seen silhouetted against the sky on the top of mountain ridges. I have seen relatively young examples less than 1 metre high at most of the localities, but even these are probably a few decades old. To maintain a population only a few seeds need to find a suitable place to germinate, but it has to be a year during which the climate permits the seedling to get to a size sufficient to survive the next dry period. The range of ages of the plants in most localities suggested to me that there were enough younger ones to keep the overall numbers stable. Other cacti can be found growing with Browningia candelaris. I have seen Armatocereus, Arequipa, Corryocactus, Loxanthocereus, Haageocereus and Tephrocactus growing with Browningia it just depends which valley you are looking in. The overall appearance of their surroundings is one of extreme aridity with little sign of life other than the cacti, which themselves often look stressed by drought.
|Figure 1. An unusual branched plant of
Browningia candelaris in the Nazca
Valley, Peru at 3.000 meters GC238.01
|Figure 2. A old flowering plant of|
Browningia candelaris, with fruit,
in the Tinajas Canyon near Lima, Peru. G157.02
Figure 3. (Insert): Flowers of the same plant
Although rainfall probably has a bearing on when browningias flower, they are usually in bloom in July or August. The fruits are then ripe in October or November in time for the ripe seeds to benefit from any rain which falls in December or January. The ripe fruits, which fall off whole, are full of pulp (Fig.5) which is said to be attractive to ants, and they may play a part in the distribution of seeds. In 1999 1 observed fruits on plants near to Tacna in southern Chile which were significantly smaller (6cm long; Fig.5) than one I had observed in Tinajas Canyon (10cm long) near to Lima in 1994 (Fig.6), although both contained ripe seeds. Interestingly, Rauh referred to certain differences in the plants from the northern end of the distribution, including the fact that they occurred at lower altitude. Ritter described these northern populations as a separate species, Browningia icaensis, stating that the two grew in the same valley where their distributions overlapped and there they were separated by altitude with a definite gap between them. In his description, Ritter gives the fruit size of B. icaensis as 10cm, rather larger than the 7cm quoted for the southern forms.
Browningia candelaris is rarely cultivated in Europe, partly due to seed being offered only occasionally and also because the seedlings are slow growing and not particularly attractive. An article in Kakteen und andere Sukkulenten (1967), the journal of the German Society by Prof. W. Rauh, described how a 3 metre high mature specimen was collected near to Arequipa and transported to the Heidelberg Botanical Garden where it flowered in 1965, probably the first (and last?) flowering of this species in cultivation in Europe. When I visited Tinajas Canyon near Lima in 1994, my friend Chris Pugh dislodged a fruit with an accurate throw of a stone. The fruit weighed over 200g (Fig.6) and contained a large number of large black seeds which resulted in many of the typical brown spined seedlings. After six years the biggest plants are about 12cm tall. My oldest plant is over 25 years old and still only about 25cm tall so I am not optimistic about being the first to flower a seedling in cultivation in Britain! Bob Ressler has grown a few from seeds and after 8 years they are as much as 1 foot high (30cm) so growth can be sped up with certain conditions.
|Figure 4. The abrupt end to the spiny,
lower part of the trunk on a plant near
the road from Arica to Putre at 2,200m
in northern Chile. GC280.01
|Figure 7. Browningia candelaris 'seedling'|
in the collection of Tony Mace.
Approximately 30cm high at 40 years old.
(Not illustrated in BCSS article)
|Figure 5. The small fruit of plants near
Tacna, at 2,670m in southern Peru.
|Figure 6. The large fruit of plants in the
Tinajas Canyon near Lima, Peru.
According to Rauh, the propagation of this plant must be done by seeds since the flowering arms cannot be rooted nor successfully grafted. This is an interesting observation which suggests that there is something physiologically different about these branches which stops them rooting, a bit like trying to root just the cephalium of a Melocactus perhaps. Before reaching this conclusion, I think it would be necessary to experimentally compare the rooting of Browningia branches with the mature limbs of other large cerei collected in habitat, since I would guess that none of these large diameter stems would be easy.
In recent years, the desire to consolidate species into fewer genera has resulted in further plants being added to the genus Browningia. Species which once belonged to Gymnocereus, Gymnanthocereus, Castellanosia, and Azureocereus are now included, making a total of about ten in all. Although they have a number of botanical features in common, none has the extraordinary form of B.candelaris.