The Echinocactanae Acanthocalycium

Ariocarpus

The Echmocaclaiuie which are described in Ihe following pages are characterized by the way in which the flowers are produced from the new year's growth at Ihe lop of Ihe plant, rather than from the sides as in the preceding group. They include some of the strangest members of the cactus family, such as Lophophora williamsii, the peyote cactus, from which mescalin is prepared, and Ariocarpus species which appear to be completely dead.

Water should be given early in April and no attempt should be made to wait for the emergence of buds. Instead, as the new growth develops from the ccntre at the top of the plant and ihe spines begin to open oui from ihe areoles. much bushier patches of wool or felt in the areoles will be seen where flower buds have been initiated during the winter resting period. For this.reason members of this group generally flower later than those of the Echinocereanae and are to be highly prized on this account. One notable exception to this generalization is Parodia chrysacaniliion which is one of Ihe earliest flowering of all the cultivated specimens other lhan ihe epiphytic cacti.

Their requirements are similar to those of most other terrestrial cacti but the specialist grower with time to differentiate between the differing needs of individual groups of plants would be advised to add a little more peat lo the soils normally used for these in contrast to [he preceding group which tended to need more sandy soils.

Acanlhocalycium violaceimi is an excellent, undemanding plant which flowers regularly once ii has attained an age of four years or so. The plant bodies make an almost perfect hemisphere and sit flat on the ground rather than developing a stem. The ribs are extremely prominent and number about sixteen. The arcóles are produced at approximately half-inch (1-cm) intervals on the raised sharp edges of the ribs and from these a number of spreading pale yellow brown-tipped radial spines arc produced. The central spines are bent upwards and give the plant a somewhat ferocious appearance.

The flowers are produced between May and August, although cultivated specimens will seldom carry them continuously over this period. They are a deep mauve in colour and contrast well with the pale green plant bodies and yellowish spines. The Greek name is derived from acanihos meaning spine and calyx meaning cup: the stems on which the flowers are produced are densely covered in short spiny scales which are the distinguishing feature of plants of this

Ariocarpus fissuratus is not really recommended for the beginner. It is inordinately slow growing and looks as though it is completely dead. It needs an extremely well-drained soil as it has a fleshy lap root which rots easily and it is often wise to start younger plants by grafting them before planting them out. I recommend the inclusion of some crushed bricks in the potting medium as this encourages the water to drain quickly. Although giving every appearance of being dead, between June and September they will reward their owners with a succession of pale pink flowers produced from amongst the woolly hairs at the top of ihe plant between the 'leaves', which have a deep fissure running longitudinally down the centre filled with more felting.

Haage recommends that no water at all is applied to the soil in which the plant is grown. Instead it should be polled up in a mixture of crushed bricks and loam and the pol placed in an outer container filled with a conventional compost. Water should then be applied to the outer container only. Care should be taken to avoid pouring water over the woolly centres. If it remains there, especially at night, it can cause damping off to start which will not only prejudice ihe formation of flowers but may also spread to the centre of the plant and encourage fungal attacks.

There are several other species of Ariocarpus but they are all broadly similar in appearance and cultural requirements and arc all comparatively ra

Astrophytum

One of Ihe more curious genera of cacti is the bishop's cap cacti, so called because the bodies of the plants resemble a bishop's mitre. They are extremely geometrical in appearance but are not difficult to cultivate once established. Astrophytum myriosligma, indeed, is one of the varieties which is most easily raised from seed.

The species illustrated above. A. listerias. is somewhat uncommon. Although it may be easily raised from seed it is the growing on that presents problems as it is very slow growing and if grown in a conventional seed tray with other seedling cacti it may damp off or be overcome by algae where this is a problem. The best idea is to allow the seed to develop normally until it is big enough to handle, the plantlet can then be removed and grafted carefully on to Tri-chocereus stock, or if warm conditions are available for the winter it can be put on to one of the faster-growing stocks such as Hylocereus or Myrtillocaclus. Although it is quite often offered for sale as a grafted specimen, after about three years when the plant is established it will grow slowly but adequately on its own roots.

The plant bodies are hemispherical and surrounded by eight ribs which are very broad, so broad in fact that the furrows between them are the only indication of their existence. The stem is mid-green and spineless and the white woolly areoles are produced like small tufts of hair at regular intervals down the sides of the ribs. It is not difficult to obtain flowers especially from grafted specimens, and although small 130 they are an attractive yellow, showing up well against the contrasting darker stems.

Astrophytum capricorne. in contrast to the previous species, is heavily protected by spines. However, the spines are not nearly as vicious as they appear being weak and somewhat bristly in texture. Like A. asterias it is very slow growing, often producing only two new sets of areoles each year. The specific name is derived from the Latin words for goat and horn as the reflexed curving spines are supposed to bear a superficial resemblance to the horns of a goat. The ribs are prominent and the plant bodies themselves are pale green to greyish green. The areoles arc in depressions on the edges of the ribs and spaced up to an inch (2-5 cm) apart on the true species. In mature specimens of the true species the spines fall off as they grow older, but there are very many different forms of this plant and these tend to have many more spines which often grow long and thread themselves into an intricate tracery round the plant bodies. The species flowers even when quite young, producing splendid yellow blooms, but most of the cultivated forms which have been bred for their spines lend to flower less

The type species to which the name bishop's cap most obviously applies is A.myriostigma. This is another completely spineless cactus and the geometrically shaped ribs, normally five in number but ranging from four to six, are densely covered with white mealy spots which give the plant bodies a grey appearance. The areoles themselves are somewhat inconspicuous and appear as little more than depressions on the sides of the ribs with a slight filling of felt. The flowers, as in both the preceding species, are yellow in colour and are produced at the top of the stem as the new areoles unfold between April and September.

There are several cultivated varieties of this plant; one. A.m.quadricostatum, retains the four-sided structure of the seedlings even when mature, and another has almost completely green plant bodies on which the mealy spots have been relegated to the extreme edges of the ribs.

Astrophytums need a sunny situation and a prolonged period of drought and low temperatures in the winter if they are to be at their best during the summer and produce a good show of flowers. Care should be taken not to overwater them as they develop a long fleshy tap root similar to that of ariocarpus.

Asirophylum ornaium is a shy flowerer although it makes up Tor this by having ornamentally banded stems as shown in the illustration. The true species is fairly well armed but there are a number of hybrids between A.ornaium and A.myriosiigma which have sought to blend the ornamental bodies of the former with the free-flowering habits of the latter. However, they are generally poorly armed and the oblique bands of woolly hairs that cross the sides of the ribs are not nearly so prono.unced.

The plant bodies are broadly cylindrical and the plant grows upwards rather than outwards as in A.myriosiigma. ultimately attaining a height of a foot (30cm) in its native habitat in central Mexico. The stems are dark green with five ribs when young which increase to eight with age. These ribs are prominent and have oblique bands of white mealy spots down the sides and often produce a few hairs as well. The spines are variable in number, with between five and eleven radials which are yellowish when young and become brown with age. The areoles are about half an inch (1 cm) apart and the younger ones have some felt in them which disappears with age.

Asirophylum ornaium is a shy flowerer and will seldom bloom when less than five years old. Plants which flower when younger are probably the hybrids referred to above and also probably lack the very prominent banding of the species, tending to have more continuous bands and less obvious patches of stem.

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