Odd plants, either fleshy, upright and leafless, or twiners, usually with opposite. Roots often tuberous. Flowers 5-lobed, the lobes generally joined to each other at the tips; some are very curious, e.g. C. haygarthii and C. sandersonii. Hearts Entangled, C. woodii, is a creeper making tubers among the small heart-shaped . Easy to grow, even in rooms; climbers best in hanging baskets. Soil rich, with extra humus. Min. W.T., 10-° C. (50 F.). P., , or aerial tubers if formed.
Chamaecereus (Cactaceae) The only species, C. sylvestrii, is the popular Peanut Cactus. It is small, making a clump of branching, more or less prostrate pale greenup to 6 in. long and 1 in. thick, with small white spines. In spring the scarlet , about z\ in. long and I\ in. across, are profusely produced. There are cristate forms and a yellow-coloured form. Nearly hardy, and best kept between 1 – 40 C. (33 – 400 F.) in winter. Easy for rooms.
Cheiridopsis (Aizoaceae) An interesting genus with many very fleshy species of varying shape. One to three pairs of leaves, each pair different. Some species make longish, triangular leaves; others have a boat-shaped pair of basal leaves and short, rounded central pair; others are small and rounded. Quite difficult, needing moderateonly in the growing period, but worth specialised study. R., early spring to late summer, quite dry. Min. W.T., 10-° C. (50 F.). P., .
Cissus (Vitaceae) Most cissus are shrubby climbers related to the grape, and there are some succulent climbers (e.g. C. cactiformis, C. quadrangularis) with four-angled, ribbed, jointed stems, with leaves and tendrils at lobes and ends, which are quitein a cool house. P., .
The really succulent species, however, are rare, peculiar and difficult. Examples are C. baitiesii, C. hypoleuca, C. juttae. For much of the year, when they should be kept quite dry, they exist as conical or barrel-shaped stems with whitish, peeling skin, from 2 -12 ft. high in nature but rarely over 1 ft. in cultiva-tion. In winter, when they should be lightly watered, they produce large, toothed, glossy leaves in a tuft, and sometimes a spray of tinyfollowed by berries. Maximum sun; soil poor, very porous. Min. W.T., 10° C. (50° F.). P., .
Cleistocactus (Cactaceae) Columnar or sometimes prostrate, many-ribbed, up to 6 ft. tall but only 1 or 2 in. thick. The flowers are narrow and tubular, about 2 in. long. C stransii is a beautiful plant covered with small white bristles, and has red flowers. The species like a rich, peaty soil, and will stand 8 ° C. (15 ° F.) of frost if dry at the.
Conophytum (Aizoaceae) One of the largest and most drought-adapted genera in the family, entirely composed of small plant-bodies, the basic pair of leaves being almost entirely merged. A few form stems when aged, and these make tap-roots. Most make clumps at ground level. The bodies are round, conical, cylindrical or ovate; some have no division; some a tiny slit in the top; others have more or less pronounced lobes. They are, will flower in rooms and can be increased rapidly. Min. W.T., 10 C. (50 °F.).R., September/October-July, when the outer skin becomes very withered; keep almost dry September-December; quite dry January-June/July. P., seed, division.
Coryphantha (Cactaceae) A large genus of low cylindrical or globular plants with more or less pronounced tubercles, resembling, but separated because of a groove in the upper surface of the tubercles. The flowers are often large, usually yellow. Prefer a peaty . Easy to grow.
Cotyledon (Crassulaceae) A confused genus close to many other members of the family, containing various types of plant. Most are attractive, easy and good indoors, W.T., min. 6° C. (420 F.), max. 10-° C. (50 F.). These include species such as C. macrantha, orbicu-lata and undulata, which resemble the shrubby crassulas. Another group, including C. reticulata and wallichiiy resemble miniature palms, with clumps of thin cylindrical leaves at the ends of long stems. These are more fussy, with a min. W.T. Of 10-° C. (50 F.), and needing to be kept fully dry in the summer rest period. The flowers are carried in clusters. P., seed, quickly from cuttings, less easily from leaves.
Crassula (Crassulaceae) A large genus of attractive plants of various forms, most worth cultivation. Leaves almost always opposite, often in cruciform arrangement, but may be spread out on long stems or tightly packed together. The small flowers in clusters are pink, white, rarely yellow. Typical of the shrubby species are C. arborescens, argentea and lactea, stout plants with fleshy, roughly spoon-shaped leaves. In C. perforata the greyish, lanceolate leaves are closely packed in alternate pairs. C. falcata has rhomboidal, crosswise-upright leaves, the whole plant being flattened in one vertical plane. It has large clusters of carmine flowers.
Some are trailers, attractive in baskets, such as C. rupestris, corallina and spathu-lata in which small leaves, joined together at the base, are strung like beads on long stems.
In C. lycopodioides the tiny leaves are packed into erect, square stems up to 2 ft. high and 2 in. thick. This is similar in structure to the ‘mimicry’ forms, such as C. pyramidalis, C. columnaris, C. quadrangularis, C. arta, C. teres; in these theis square or rounded, and the leaves are so close that a nearly smooth surface results. Lastly there is a group of low-growing, very succulent forms, including C. cornuta, C. tabularis, and C. tecta.
Most of the species are easy to grow and do well in rooms, with a max. W.T. Of 10-° C. (50° F.). The ‘mimicry’ forms are for the expert, and should be kept to the, needing a min. W.T. Of 10° C. (50 F.), and to be rested, nearly dry, in our summer. The last-mentioned, fleshy forms need similar conditions and rest in our winter. P., seed, readily by cuttings, also from leaves. Delosperma (Aizoaceae) Most are small shrubs with smallish leaves, often covered with raised dots and hairs, giving a silvery, sparkling look. Commonest is D. echinatum. They flower freely and for many months, with small whitish or reddish blooms. W.T. Min. 6° C. (420 F.), max. 10-° C. (50 F.). P., seeds, cuttings.
Dorotheanthus (Aizoaceae) The Livingstone Daisy, a delightful and showy little-. Seedsmen sell it as Mesetnbryanthe-mum criniflorum, but the packet usually contains hybrids which produce flowers white, buff, pink or carmine, sometimes banded in two colours, about I-\ in. across. These are superior to the species D. crmiflorus and D. gramineus, and varieties of the latter. They are classed as half-hardy , but are quite tough and may be sown in cold frames in March or where they are to grow in mid-April or later. Thin out well. A well-drained sandy soil is best and a sunny essential for the flowers to open properly. Pick off dead flowers for continuous .
Drosanthemum (Aizoaceae) Bright shrubby plants with small cylindrical to triangular leaves covered with sparkling raised dots. The rather small red or white flowers are very freely produced, and the plants are useful for bedding out. W.T. Min. 6° C. (42° F.), max. 10-° C. (50 F.). P., seed, cuttings. Echeveria (Crassulaceae) A large genus (with many synonyms ) of attractive rosette plants, sometimes on stems, which make large clumps quite quicklv. Leaves often waxy or glaucous. The dainty urn-shaped flowers, red, orange, yellow or white, are carried on long stems. Most flower in summer, but some in winter. E. glauca is often used for carpet-bedding. All are attractive; recommended are E. gibbiflora, perelegans, gigantea (nearly 2 ft. across), setosa, retusa and puberula. Best kept under glass are E. cotyledon, densiflora and farinosa. They will grow in rooms, but the flowers may then dry up before opening. W.T. Min. 6° C. (42 F.), max. 10-° C. (50 F.); cold frames will do for bedders, kept almost dry. P., seed, cuttings of almost any part.
Echinocactus (Cactaceae) Round or barrel-shaped, flattened at the top, covered with fearsome spines. The flowers are smallish, seldom produced in, although E.horizon-thalonius will do so when quite young. E. grusonii is common; it will grow to nearly 3 ft. across and has interlacing golden spikes up to 3 in. long. Rich soil preferred. Echinocereus (Cactaceae) A large genus with soft fleshy stems up to 15 in. long and 1 – 3 in. thick, erect or prostrate, making spreading clumps. Some have spines, others none. The flowers, white, yellow, red or purple, are fairly large. They are easy to grow and many are quite hardy. There is little to choose between the many attractive species. W.T., 1 – 4° C. (33 – 400 F.). Cuttings should be taken in late June and July.
Echinopsis (Cactaceae) A popular window-sill plant. Usually round or cylindrical, rarely columnar; spiny, with marked ribs. Characteristically flower very freely even when young, with large, long-tubed pink or white flowers of great beauty. Many hybrids exist. Occasional sports occur which produce myriads of offsets; these plants seldom flower. Easy to grow; many fairly hardy.
Epiphyllum (Cactaceae) Shrubby epiphytes with flat or 3-angled-like joints, often notched, seldom spiny. In the species the flowers are usually small and open at night; it is the hybrids, often crosses with Hel10-cereus or the Hylocereus tribe, and commonly called , which are best known, with large very beautiful flowers of almost every colour except blue. Sometimes grafted on Hylocereus undatus. They like rich but porous soil , half-shade, plenty of water when growing, fairly dry when not. Watering should be reduced for a few weeks after flowering. They appreciate a lot of air in summer and, unlike most succulents, a damp atmosphere obtained by regular syringing. Hence they are more suitable for growing in a mixed greenhouse than with other succulents. Min. W.T., 70 C. (45 ° F.).
Euphorbia ( Euphorbiaceae) This is one of the largest genera of plants and includes a number of diverse succulent forms. Many-make tree-like growth, and many resemble, apart from the flowers, which are usually insignificant. It is difficult to make a selection from at least 100 succulent species. Some are more woody than succulent, like the brilliant red-flowered E. splendens and E. bojeri, often called Crown of Thorns. Other woody species with leaves are E. alcicornis, canariensis, lophogona – the latter with white leaves and red stalks.
Among the cactiform are the jointed, 4-angled E. abyssinica and E. similis; 3-winged, fierce-spined E. grandicornis; and square-stemmed E. resinifera. E. horrida is like a spherical. E. caput-medusae has radiating branches from a central head. There is a tuberous-rooted group, including E. aequoris, almost totally buried, and E. namibensis with parsnip-like and many short, bristly branches. Of most interest, perhaps, are the very fleshy forms, such as the spherical or oval E. obesa. The prominently ribbed E. meloformis resembles an astrophytum. E. bupleurifolia is an example of a type which is covered with scales, which are in fact -cushions, and has long narrow leaves on top.
In fact, the euphorbias should be in any collection, and are a perfect subject for a specialised one. They are mainly easy to grow, needing a min. W.T. Of 70 C. (450 F.), and do well in rooms. The leafy forms are rich feeders and like much water in summer; the really succulent ones need special care withand watering – usually no water in winter. P., seed, cuttings. Caution — the typical milky juice (latex) is and must be kept from eye, mouth or any cut. Faucaria (Aizoaceae) Small clump-forming plants with 1 – 3 pairs of thick, triangular leaves, which have teeth or spines on the edges — hence the apt name Tiger’s Jaw. The large yellow flowers appear in autumn. Easy to grow, good in rooms. W.T. Min. 10° C. (50°F.), max. 13 °C. (55 ° F.). R., spring and summer. Free watering in winter, sparingly in summer. P., best from seed, also cuttings.
Fenestraria (Aizoaceae) Difficult but interesting; a ‘window-plant’, forming large clumps of leaves, about 1 in. long, round in section and thickening towards the flattish translucent top. In nature these are buried up to the top. The pale orange flowers are very large – up to 3 in. across — in the commonest species, F. aurantiaca. Need bright; compost mainly of sand. Min. W.T., 6° C. (420 F.). R., September/October-February, when very little watering is required. Little water even in growing period. P., seed, or division of clumps, but resents disturbance, including .
Ferocactus (Cactaceae) Spherical to cylindrical plants, some becoming very large (e.g. F. diguettii, 12 ft. high, 3 ft. across), with marked ribs, and a heavy array of long thick spines, usually attractively coloured, the central one often hooked and sometimes 5 in. long. The flowers are relatively small but showy, red, yellow or violet. All are worth growing. They like heavy, rubbly compost, and should be watered very cautiously.
Gasteria (Liliciceae) Typically with thick, tongue-like, pointed leaves in two ascending rows, sometimes spirally twisted when older; a few make rosettes. The leaves are often covered with white tubercles (e.g. G. verrucosa). The quite showy flowers are like those of Aloe, and cultivation is the same, though they dislike direct sunlight. G. neliae is attractive, with horny edge and regular white flecks on bright green leaves. G. acinacifolia forms a rosette of white-spotted, foot-long leaves. Tough plants, useful in rooms. P., seed, offsets,.
Gibbaeum (Aizoaceae) Interesting but difficult; very succulent plants with I or 2 pairs of leaves, making clumps. Some are roughly spherical (e.g. G. album, G. pilosulum); some egg-shaped (e.g. G. dispar); some have finger-shaped leaves, short and blunt in G. perviride, longer in G. pubescens and more angular in G. nelii. G. velutinum makes flat, triangular leaves. Most are curious in that the leaves of a pair are of different sizes, and the division between them is oblique. Small white or pink flowers. Growing period varies between species, from winter to early summer; water lightly then, keep quite dry when resting. Min. W.T., 10 ° C. (50 ° F.). P., seed, cuttings.
Glottiphyllum (Aizoaceae) The name means ‘tongue-leaf and is apt. The leaves are usually longer than wide, but sometimes short and broad, thick, fleshy, irregular, very soft and waxy to touch, generally a bright green; they typically radiate at ground level from a number of-like growths, and flower freely with large yellow blooms. Little to choose between species except leaf-shape. Easy to grow. R., February—May, quite dry and cool. Moderate water in growing period. P., seed (may not be true); cuttings best.
Greenovia (Crassulaceae) Very similar to Aeonium, but always on short stems; cultivation the same. Rosettes which have flowered die. Few species: G. aizoon has white-haired rosettes 2 in. across. G. aurea makes cushions of large glaucous rosettes and G. gracilis has small rosettes, in each case like rosebuds. Good room plants. W.T. Min. 6° C. (420 F.), max. 10-° C. (50 F.). R., late summer-winter, when rosettes close up; keep fairly dry. P., seed, quicker from cuttings.
Gymnocalycium (Cactaceae) Curious but attractive globular cacti, ranging from 1 -12 in. across, but mainly small, with rounded ribs divided into low tubercles, each carrying a few smallish spines. Many species and hybrids, all decorative, with quite large white or pink flowers (red in G. baldianum), usually freely produced and on young plants. Easy to grow; rich soil, much water in the summer. Many are fairly hardy; they prefer half-shade.
Haworthia (Liliaceae) Mainly rosette plants, some remaining low, some ascending, a few with leaves in two rows. Some have very hard, tubercled leaves, as H. margaritifera and H. fasciata; some are bristly (H. altilinea); others have soft, translucent, triangular leaves, such as H. cooperi and cymbiformis, and the netted H. tessellata. In various fleshy forms the rosettes are, in nature, buried to expose only the flat leaf-ends, as with H. retusa and the most adapted forms, H. maughanii – a little like Fenestraria – and H. truncata, with two rows of thick, flattened, crowded leaves. The long-stalked flowers are insignificant. Most are easy to grow and thrive in rooms, but the last two mentioned need treatment more as for Lithops. Otherwise cultivation as for Aloe. W.T. Min. 6° C. (420 F.), max. 130 C. (55° F-)- R-> winter, when water moderately. P., seed, offsets. Repot in late summer.
Heliocereus (Cactaceae) Usually trailers, with thin stems, remarkable for their large, beautiful, strong-scented flowers, for which they are called the Sun. These may be red, often with touches of green, purple or white, and up to 6 in. long. H. speciosus is usuallv seen, and is one of the parents of many of the hybrid epiphyllums. Like them, these plants need heat, some air moisture, peaty soil and half-shade. A little bonemeal may be given. Min. W.T., 70 C. (450 F.).
Hylocereus (Cactaceae) Epiphytic plants with aerial roots; stems long-jointed, notched, angular or winged, with a few small spines. The usually nocturnal flowers, often scented, have white petals and red, purple or green sepals, are sometimes very freely produced, and are large – generally 6-8 in. and in some cases 12 in. long. The fruits are also large. They need warmth, air moisture and a free root-run to flower, and prefer very rich, peaty soil, without lime, and half-shade. H. undatus and H. triangularis are commonly seen, and are often used as grafting stocks for pendulous plants.
(Crassulaceae) Closely related to Bryophyllum, but not producing adventitious buds. Erect, sub-shrubby plants, often becoming large, with opposite leaves and large clusters of small bright flowers, white, red or yellow. The flower-bearing shoots die afterwards, but new growths arise at the base. K. blossfeldiana, with scarlet flowers in winter and spring, is grown commercially, and K. flammea (orange-red) and K. pumila (pink) are equally good value. Modern hybrids have larger flowers. In others the leaves are the main attraction: K. grandiflora has bluish, rounded, notched leaves; K. marmorata greyish leaves of similar shape with handsome brown markings; K. pruinosa long, pointed, notched, glaucous leaves; K. tomentosa is covered with silvery fur, reddish-brown at the leaf-tips; while K. beharensis soon grows large with big, felted, wavy leaves.
Easy to grow, usually good in rooms. The flowering kinds are grown rather like Rochea coccinea, being kept in shaded frames and cut back in late June. W.T. Min. 6° C. (420 F.), max. 10-° C. (50 F.). P., seed, cuttings.
Kleinia (Compositae) A genus of several very interesting plants, most quite easy to grow in rooms. Modern classification places these under. The most commonly seen is K. articulata, the Candle Plant, which has blue-grey, jointed stems and, for a short season, ivy-shaped leaves. K. anteuphorbium has very long joints and lanceolate, silver-grey leaves. K. ficoides and K. repens are more prostrate plants, with narrow leaves and rigid joints. K. neriijolia, which eventually makes a 10-ft. Bush, looks like a miniature palm-tree. Most interesting is K. gomphophylla, which has prostrate stems rooting as they go, with leaves like green acorns. They have pale stripes which are in fact ‘sun-windows’. This is a desert plant and needs less water than the others, but all need cautious watering, particularly K. tomentosa, a very attractive plant forming 12-in. Clumps with cylindrical leaves, pointed at both ends, about I\ in. long, the whole covered with close white felt. It is very sensitive to changes of temperature. Keep all kleinias nearly dry in summer.
W.T., min. 6° C. (420 F.), max. 10-° C. (50 F.). P., seed or cuttings; the joints, which are easily detached, root rapidly. Repot in early autumn.
Lampranthus (Aizoaceae) More or less shrubby plants, with fairly distant leaves, usually long and narrow. They flower freely during most of the summer, and are much used for bedding, particularly in milder localities. They are also attractive pot and basket plants. The nurseryman will call most of them
Mesembryanthemum. There are very many attractive species, most with 2- or 3-in. Flowers. Among the pink ones are L. blandus, roseus and falciformis; reds include scarlet L. coccineus, purple-carmine L. conspicmis, purple-red L. haworthii and L. spectabilis. L. zeyheri is a brilliant violet-purple; L. amoenus is mauve; L. glaucus a large yellow; L. aurantiacus is orange; L. tenuifolius orange-scarlet; L. aureus yellow or orange. All need only protection from frost and to be kept nearly dry in winter. They can be overwintered in a light, airy room. P., seed, cuttings best.
Lemaireocereus (Cactaceae) Growing into tree-like clumps, with stems 3 — 6 in. thick, and with short, often coloured spines. Most branch freely, but L. marginatus, often used as a hedge-plant in Mexico, grows straight up. The ridges of its ribs are topped with wool. Flowers usually small; the species are prized more for their form and colouring, especially good in. Cultivation as for Cereus. Min.W.T.,6°C.(42°F.).
Leuchtenbergia (Cactaceae) L. principis, the only species, is a remarkable cactus with long root, woody stem and very long triangular tubercles, 5 in. long and f in. across, with papery spines 4 in. long at the ends. The yellow flower is I\ in. across. Easy to grow in porous soil: much water while in growth. Seedlings grow fast, flowering in 4 or 5 years. P., cuttings of tubercles. Lithops (Aizoaceae) A large genus of very fleshy plant-bodies, often coloured and patterned and resembling stones, and in nature buried up to the top, living in the hottest desert conditions. The bodies are conical or cylindrical, and the two leaves which compose each are completely joined, apart from a more or less pronounced cleft in the top. The yellow or white flowers appear in the cleft, and are usually bigger than the body; the top is flat or slightly convex.
The species are all basically similar, but vary in markings and size, the latter from about £ — if in. in height. In cultivation they often exceed the natural size. It is best to grow them in separateand, since they like very hot sun, to sink the pots in a gravelly bed. This avoids root-scorch. Very sandy soil is necessary. Watering should always be cautious, and none given in winter. They can be grown on a sunny window-sill. Min. W.T., 10 ° C. (50 ° F.). R., November/January-April/May. P., seeds; cuttings can also be used or clumps divided.
(Cactaceae) A large genus of small, round or cylindrical, ribbed, spiny plants, with relatively large flowers, usually red, (L.nealeana, L.famatimensis, L.hertrichiana), sometimes orange (L.drijveriana), or yellow (L.haageana and L.famatimensis aurantiaca). There are numerous hybrids. They are very free flowering and easy to grow, preferring some shade and rich, limy soil; cool in winter.
Lophocereus (Cactaceae) The one species, L. schottii, grows to 15 ft., about 2.\ in. thick, with thick spines and many bristles. The flowers are small. It is the monstrous form, often labelled Cereus or Lemaireocereus mieckle-yanus, that is usually grown — an extraordinary sight with irregular ribs, quite spineless and smooth. Water cautiously.
Lophophora (Cactaceae) L. williamsii is notorious as mescal or peyotl, the dried form in which it was eaten by the Mexican Indians, since it contains powerful intoxicating and narcotic alkaloids. Fairly easy to grow, it is one of a group (mainly difficult) of cacti which look more like round, grey, scaly potatoes, with low tubercles and wool-bearing areoles. There is a large tap-root. Flowers smallish, pink to white. Needs heavy, porous soil. Rather slow from seed.
(Cactaceae) At least 240 species, mainly globular, sometimes cylin-drical, all with tubercles, which have spines at the apex and often wool in the axils. Flowers smallish but attractive, usually in a ring round the top, followed by red fruits. There are too many – mostly attractive and easy to grow — to give any list of species. Good room plants. The genus is divided into two sections, one with watery sap and the other with milky sap (which may only be in the body and not the tubercles). The former need plenty of water in summer, the latter less. Many are very winter-hardy if dry.
Mesembryanthemum (Aizoaceae) As now understood, this – the original name-genus of the family – is confined entirely toand , of which Dorotheanthus and Mesembryanthemum crystallinum are often grown. The latter, sometimes called Cryqphytum or , is grown for its sparkling, spoon-shaped leaves. Nurserymen, however, continue to use the name for many shrubby species, especially Lampranthus, and it is used loosely to denote any member of the tribe.
Notocactus (Cactaceae) Usually globular with flattened top, ribbed, spiny, up to 6 in. across; rarely cylindrical, as is N. leninghausii, 3 ft. tall, which is laced with golden bristles. Flowers prolific, up to 3 in. wide, but mostly smaller, mainly yellow. Good species include N. concinnus, flortcomus, ottonis, scopa. Fairly riqh soil. Very hardy.
Ophthalmophyllum (Aizoaceae) Small plants, up to 1 2 in. high, very like Lithops, but with pronounced rounded lobes, often translucent. Flowers pink, reddish or white. Soil should be very sandy. Min. W.T., 10° C. (50 ° F.). R., March-August, quite dry, even for. P., seed.
Opuntia (Cactaceae) About 300 species, divided into four well-marked: Platyo-puntia, the largest, with flattened round or oval joints; Brasiliopuntia, with a cylindrical main stem; Tephrocactus, with spherical or ovoid joints; and Cylindropuntia with columnar stems or long cylindrical joints. Some have primitive, usually awl-shaped leaves which generally fall off soon (e.g. O. subulata). Most are spiny, the spines some-times papery (O. papyracantha), but mainly stiff – 4 in. long in O. aoracantha. Always with glochids (tiny barbed bristles) in the areoles, which make the plants very unpleasant to handle. Flowers usually large, of various shades of red, orange or yellow. With areoles and spines, often sweet and edible -hence the name Prickly Pears. Few, however, flower freely in pots; O. compressa is an honourable exception. Mainly easy to grow in any limy, porous soil, very hardy if winter wet is kept off. A few are difficult. Many are too big for the small collection, but the small kinds are attractive. P., easy from joints.
Oscularia (Aizoaceae) Attractive shrubby plants with small greyish leaves, in O. caulescens with small teeth and in O. deltoides large ones. The small, prolific flowers are pink. Cultivation as for Lampranthus.
Pachyphytum (Crassulaceae) Attractive plants with thick stems and leaves, usually rounded, ovate or spoon-shaped, purplish, greyish or with a white bloom. Like Echeveria, with similar flowers; cultivation the same, but unsuitable for bedding out.
Parodia (Cactaceae) Small globular or cylindrical plants, usually 2 or 3 in. through, with marked ribs and small tubercles, very spiny, often woolly. Many flower very freely, with small red or yellow flowers; some are decorative with coloured spines and wool. Attractive plants and very hardy. Cultivation as for Notocactus.
Pelargonium (Geraniaceae) Our familiar ‘geraniums’ are of course quite fleshy, and there are several desert forms. The leaves are similar to those of the bedding varieties, and drop in the rest period, which is usually summer. P. gibbosum has slender stems and swollen nodes; P. tetragonum has angular, jointed stems. P. echinatum is quite cactuslike with thorn-like growths. Others with short, much swollen stems are P. carnosum, crithmifolium and paradoxum. The attractive flowers are white or pink. W.T., 130 C. (55° F-)- P- seed, cuttings.
Pereskia (Cactaceae) The most primitive cacti, barely succulent, very spiny, with woody stems, and large, glossy leaves which mav drop off in the rest period. Areoles large and woolly. The flowers are 1 – 3 in. across, usually in stalked clusters, white, yellow or pink, often scented, with leaf-like bracts. Fruit pear-shaped, sometimes edible. P. aculeata godseffiana is most generally grown, with white flowers and variegated leaves, purple on top, crimson below. Often used as grafting stock for epiphytic cacti. Though rarely grown, they are attractive as well as curious. Need plenty of water and rich heavy loamy soil. Cuttings should be inserted without any drying off.
Pleiospilos (Aizoaceae) Plants with 1 — 4 pairs of leaves, making clumps, the leaves usually roughly triangular and very thick, grey to brownish, with small dots, resembling pieces of granite. Flowers large, red or yellow, sometimes several together. P. bolusii is often seen, with very broad, short leaves. P. nelii has neat hemispherical leaves and P. magni-punctatus has green, heavily-keeled leaves. All species are interesting. Prefer very sandy soil. Repot with caution. Min. W.T., 10-° C. (50 F.). R., January-September, quite dry. Water freely as leaves develop, then moderately. P., seed, division of clumps.
Portulaca (Portulacaceae) P. grandiflora is familiar as a half-hardy; it has radiating, prostrate stems with cylindrical leaves and bright flowers, which are red in the species, but in the garden hybrids are both single and double and of many colours. Cultivation as for Dorotheanthus, but is a little less hardy. Makes an attractive pot plant.
Rebutia (Cactaceae) Small, spiny plants, tubercled like Mammillaria, 1 or 2 in. across, popular for the freedom with which the small flowers, in a great range of colours, are produced, over a long period. R. minuscula is one of the smallest cacti, 1^ in. across, 1 in. high with 1^ in. flowers all spring and summer Very easy to grow.
Rhipsalidopsis (Cactaceae) Modern authors may submerge this genus in Rhipsalis. The, R. gaertneri, is a pendulous epiphytic cactus with bright scarlet flowers in spring. (It used to be called gaertneri.) R. rosea is a small plant with more open pink flowers, also flowering in spring. Cultivation as for Epiphyllwn.
Rhipsalis (Cactaceae) Epiphytic plants from tropical forests, with cylindrical, flat or angular joints, and woolly bristly areoles. Growths often branching, prostrate or trailing with aerial roots. Small starry flowers, white, pink, red or greenish, with few petals profusely produced in winter. Need overhead spraying and warm humid air conditions, little watering, rich, very peaty but porous soil, and much shade. Suitable for anhouse, and will grow in orchid compost.
The Rhipsalis are noteworthy as the only cactus genus native to Africa and Ceylon as well as America.
Rochea (Crassulaceae) R. coccinea is the florist’s ‘Crassula’, with stems up to 2 ft. high, thin triangular leaves arranged crosswise and fairly closely packed, and showy tubular carmine flowers in terminal clusters. These appear in early spring if forced, later if not. There are other equally attractive species, in which the flowers may be white, pink, yellow or red. Easy plants, good in rooms. Min. W.T., 4 – 70 C. (40 – 450 F.). P., seed, usually from cuttings (best in late spring).
Schlumbergera (Cactaceae) The correct name of the, so long called Zygocactus truncatns, is now accepted to be Schlumbergera buckleyi; it is in fact a hybrid of more vigour than its parents. The schlum-bergeras are epiphytic, pendulous plants, much branched, with short, flat, notched, leaf-like joints. 5”. buckleyi has deep pink flowers, and there are numerous other hybrids and varieties in white, red, violet, although these are not at present easily available in the trade. The leaf-like stem sections have scal-loned edees. In S. truncata and its forms, such as Koenigers Weihnachtsfreude, the flowers are distinctly more zygomorphic -that is, they are largely symmetrical only in the vertical plane, while the leaves have triangular or pointed teeth. The flowers of schlumbergeras, 3 in. long and 1 in. across, are profusely produced in autumn and winter, and last well. Cultivation is as for Epiphyllwn; plants are good in rooms in equable conditions. They are sometimes grafted on to columnar stock to make a ‘standard’, or may be grown in hanging baskets.
(Crassulaceae) A genus of at least 50 species, mainly hardy, many commonly grown and a number native to Britain. Some of these can be grown in pots, but tend to grow too large. The tender kinds only are normally included in a greenhouse selection, and these, are mainly Mexican, with a few from Madeira. They are all attractive plants, forming loose rosettes or spiral groups of leaves at the end of fleshy stems, and vary from several feet high to small prostrate plants. The leaves are of many shapes and may be green, red, bluish or whitish, and the flowers, usually small in clusters, are of several colours.
Among tall-growing species, which tend to grow straggly, are S. adolphii, dendroideum, nussbaumeri and treleasei, with large roughly boat-shaped leaves; S. praealtum, with long flat leaves; »S. palmeri, with flat, rounded leaves; and S. compressum, with leaves oblanceolate and flattish. Perhaps the most attractive are S. allantoides, pachyphyllum and guatamalense, the first two whitish, the latter purplish; S. bellum, with mealy-white, spoon-shaped leaves; and’S. Farinosum, with mealy, awl-shaped leaves. S. stahlii is a small spreading plant with reddish, oval leaves \ in. long. An unusual species, 5”. morganianum, has pendulous chains of leaves.
All are very easy to grow. W.T., min. 40 C. (400 F.), max. 10-° C. (50 F.). P., cuttings, division, usually easy from leaves.
Selenicereus (Cactaceae) Trailers or climbers with long, thin, ribbed, branching stems, usually with small spines and aerial roots. The flowers are immense, cup-shaped, around 8 in. long and across, on a long tube. They are white or tinged with red, purple, yellow or green, with radiating sepals and many stamens. Mainly night-flowering, fading soon after daybreak; often very sweetly scented. Old plants will flower over 2 or 3 months. They like a rich, peaty, limy soil, and need some warmth, much water and overhead sprays through spring and summer. 5. grandiflorus — of which Prof. Borg wrote ‘No collection of cacti should be without this marvel of the vegetable kingdom’ — is called Queen of the Night; all are known as Moon Cacti.
Sempervivum (Crassulaceae) Rosette plants with flower spikes bearing terminal clusters of flowers in many colours, not usually admitted as ‘succulents’ by the purist owing to their complete hardiness; but they make attractive pot plants for cool conditions. Many have nice red or purplish tints on the leaves and some are ‘spider-webbed’ (S. arachnoideum, etc.). Many plants are hybrids. Porous soil; dry in winter. P., offsets.(Compositae) The succulent members of this vast genus, which contains the familiar groundsel, now technically includes species treated here under Kleinia. Cultivation is identical and most are well worth growing. The adaptations to dry conditions vary a lot. At one extreme is 5. stapeliiformis, with grey-green stems like a , but with the typical reddish-orange flower of a weedy Composite — a species needing to be kept very dry. S. fidgens has a flask-shaped stem and a spiral bunch of round, flat, glaucous leaves, up to 4 in. long. Several form clumps of short stems and have prostrate branches, like S. adenocalyx; S. scaposus and S. vestita have a rosette of glaucous leaves.
(Asclepiadaceae) Many species and hybrids of low branching plants with fleshy, upright, quadrangular stems, toothed on the angles, with short-lived or no leaves. Remarkable for the bizarre, surrealist flowers, usually with a yellowish background more or less marked with brown, dark red or purple, often hairy and usually with a powerful carrion smell that attracts the blowflies that fertilise them – hence the name Carrion Flower. A few are odourless and one or two pleasantly scented. The flowers appear in mid-summer, and have a tube and a bell- or star-shaped corolla, more or less cut into 5 lobes, with a central fleshy ring (the corona); they vary from I – n in. across. The fruits are horn-shaped, two to a flower, appearing months later. The medium-sized S. variegata is most often seen. Easy to grow, even indoors, preferring air moisture in summer and enjoying spraying on hot days. Rich, humus-containing, porous soil. Reduce watering towards autumn, keep fairly dry in winter. Min. W.T., 10-° C. (50 F.). P., seed, but this may not be true, best by cuttings. Stomatium (Aizoaceae) Small almost stem-less plants with 2 or more pairs of leaves, semi-circular or triangular in section, often with toothed upper edges. Flowers fairly small, yellow. Easy plants. Min. W.T., 70 C. (45° F.). R., autumn-spring. P., seed, cuttings.
Zygocactus See Schlumbergera.