MANTHE Notes on their cultivation and propagation, with particular reference to bicolor.

The increasing awareness of limited water resources, particularly during the summer months in the Western Cape, and the need to grow waterwise indigenous species 'in our gardens, must focus attention on our wealth of winter­ growing bulbous , most of which are deciduous and escape summer drought by under­ ground dormancy. Chasmanthe is a small irid consisting of three winter-growing, summer dormant species endemic to the winter rainfall region of the north­ western, Western, southern and Eastern Cape. These are the low-growing Chasmanthe aethiopica, the medium-sized C. bicolor, and the robust, tall-growing C. floribunda.

Chasmanthe aethiopica growing wild in the Cape Peninsula's Silvermine Nature Reserve. Photo: G. Duncan.

lants of Chasmanthe, probably where it tolerates wind, sandy soil, Chasmanthe aethiopica C. jloribunda, were cultivated in minimal winter watering and summer Commonly known as 'suurkanolpypie', PEurope as far back as the early drought, as well as lightly shaded this is a relatively low-growing, 1630s, and this species is recorded as gardens with loam soils and heavy gregarious 25-70 em high with having been in flower in Paris in winter rainfall, or even hot and dry the widest distribution of the three 1633, and was illustrated and inland gardens in full sun. They all species of Chasmanthe. It occurs in a described there for the first time in produce narrow, curved flowers with variety of habitats including acid sand 1635. Often considered too 'common' arching , and long, sword­ and heavy clay mainly in coastal areas to grow by gardeners in , shaped leaves. The generic name is from the western part of the south­ Chasmanthe is an excellent choice for derived from chasme and anthe, western Cape, to the southern Cape a variety of gardens in frost-free areas which refers to the gaping mouth, and and south-eastern part of the Eastern including difficult, seaside gardens the flower, respectively. Cape. The is slightly conical and

108 Veld Er Flora September 2001 var. duekittii is just as easy to grow as Chasmanthe bieolor, unlike the other two species, is extremely the more common orange form (see cover). Photo: G. Duncan. rare and possibly extinct in its natural habitat in the districts of Robertson, Caledon and Franschhoek in the south-western Cape. Pholo: G. Duncan. somewhat flattened, surrounded by the western and south-western parts grows up to 45 mm in diameter. Its several layers of fibrous corm tunics, of the Western Cape, but it also occurs flowers are arranged alternately on and grows up to 45 mm in diameter. inland on sandstone in montane both sides of the peduncle and its It is the earliest species to flower, habitats in the western part of the dark green, soft-textured leaves are from late April to June, sometimes to Northern Cape. It has a large, flattened produced in a narrow fan-like July or August, and occurs naturally corm up to 100 mm in diameter, position, and closely resemble those on the Kirstenbosch estate, where it is which is surrounded by several layers of C. floribunda, but are shorter and frequently encountered in semi-shade, of tmlgh corm tunics. Its distribution much narrower. growing on moist sandstone in large is mainly coastal, and its flowering It blooms from July to early colonies. Its flowers are arranged period extends from mid-July until September and the highly ornamental, alternately on the upper side of the mid-September. dark red flowers are marked with peduncle, and the is There are two colour varieties, the yellow and bright green, and are unbranched. In addition to its striking most common of the two being the curved to a much greater degree than dark reddish-orange flowers and erect, reddish-orange variation Chasmanthe in C. aethiopica and C. floribunda. It somewhat fleshy bright green leaves, floribunda var. floribunda. The much is a particularly floriferous plant and its ripe capsules are particularly less frequently seen primrose-yellow unlike the other two species, each attractive when they split open and form known as Chasmanthe flori­ mature corm flowers every year, and reveal their large, bright orange seeds. bunda var. duckittii is restricted to the flowers are longer-lasting than the just a few localities near Darling in other two species. During the bud Chasmanthe j/oribunda the south-western Cape. It flowers stage, the top of the inflorescence is Commonly known as 'suurkanol' and slightly earlier than the orange form conspicuously bent downwards, but 'Adam's rib', this is probably the most and both produce branched inflores­ straightens out during the flowering well known Chasmanthe species. It is cences and brownish-orange seeds. period. The inflorescence is usually a robust plant growing up to 1.5 m unbranched but may occasionally high with long, broad, erect, soft­ Chasmanthe bie%r develop small branches at its base. textured leaves, produced in a narrow This is a medium-sized plant growing Copious amounts of small dark fan-like position. The horizontal from 70 cm to 1.3 metres high, but reddish-maroon seeds are produced. arrangement of the up to forty unlike the other two species, is elongated individual flowers on both extremely rare and possibly extinct in Pollination sides of the peduncle has given rise to its natural habitat in the districts of The long curved perianth of the the very descriptive Afrikaans collo­ Robertson, Caledon and Franschhoek Chasmanthe flower is an excellent quial name of 'Adam's rib', alluding to in the south-western Cape. The corm example of how certain southern a human ribcage! It is most frequently is slightly conical and somewhat African bulbous species with large, seen in acidic, humus-rich soil flattened, surrounded with several brightly coloured flowers have between cracks of granite outcrops in layers of dark brown corm tunics, and ensured their survival by adapting to

Veld &- Flora September 2001 109 far too short and frost-free parts of summer-rainfall straight to reach areas, a thorough watering once per the nectar by fortnight is necessary throughout the approaching the winter-growing period, up until early flower from the spring. No supplementary liquid front, have been feeding is necessary during the seen to pierce the growing period, but the addition of lower sides of slow-release granular fertilizer such as Chasmanthe Osmocote or Horticote is beneficial. bicolor perianth As temperatures rise towards early tubes in the summer, the begin to enter Kirstenbosch bulb dormancy, indicated by a browning of nursery, thus the leaves, which should be cut back gaining access to to just above ground level when fully the nectar. desiccated. Although Chasmanthe prefers a completely dry dormant Cultivation period during the summer, the corms For frost-free are tough enough to withstand areas, few winter­ summer rainfall or irrigation, growing cormous provided that the soil drains freely. plants are as As far as I'm aware, Chasmanthe trouble-free and corms are not frequently taken by easy to grow as mole rats under cultivation, but Chasmanthe. All porcupines will certainly eat them in three species are place of their favourite meal of recommended for Zantedesehia aethiopica rootstocks garden cuIti­ when the latter is not available. vation, and The earliest species to bloom is the C. bicolor also deep reddish-orange Chasmanthe does well as a aethiopica, which has a very long container plant. flowering period extending from late e. floribunda April until the end of July, depending prefers a full sun on the wild origin of the clone being position and the cultivated. This species forms large smaller colonies if left to its own devices, but e. aethiopiea and interestingly, only about fifty percent C. bieolor are of the mature corms in a large colony , inexplicably neglected by gardeners, is ideal candidates will flower in any given season. It is ideally suited to garden and container cultivation. Photo: G. Duncan. for difficult, semi­ not yet known why this is, but it is shaded parts of evident in their natural habitat as well the garden, but as under cultivation. pollination by . The are equally successful when grown in Chasmanthe aethiopiea is a partic­ Chasmanthe perianth tube is very full sun. All three species will grow ularly useful species for difficult, narrow at its base, but widens and flower in even the poorest of soils semi-shaded parts of the garden as abruptly to form a broader cylindrical but to achieve excellent flowering, a well as for sunny rockery pockets, and tube above, and has one or more rich, well-drained soil is recom­ does equally well in clay or sandy shallow or deep pouches at the point mended and large quantities of fully soils. In rockery pockets, this species of widening, which contain nectar. decomposed compost and a few can be effectively interplanted with The long, curved beak of the lesser handfuls of tlonemeal should be spring-flowering bulbous species like double-collared , the worked into very sandy soils. When Babiana angustifoiia, Ixia maeulata malachite sunbird and the orange­ grown in the open garden, and Watsonia laccata. breasted sunbird (the three main Chasmanthe species should be left The ubiquitous Chasmanthe pollinators of Chasmanthe) which undisturbed for three to four years, so floribunda is a spectacular plant, seen they insert into the perianth tube and thorough preparation of the soil is to best advantage massed together in probe the pouches for nectar, perfectly required to ensure good flowering. large beds, and is successfully grown match the curved shape of the The large flat, pancake-like corms at Kirstenbosch interplanted with Chasmanthe flower. The sturdy of e. floribunda should be planted deciduous or evergreen, summer­ peduncle provides a suitable perch for about 20 cm apart, with about 5 cm of flowering Agapanthus species like the the bird to cling to while feeding, and soil over the top of the corm to deep violet Agapanthus inapertus in the process of inserting its beak prevent them from falling over in subsp. pendulus 'Graskop' and the into the perianth tube, pollen from the strong wind. The much smaller corms pale greyish-white A. praecox subsp. arching stamens above is deposited of e. bieolor and e. aethiopiea can be minimus 'Storms River'. It can also be onto the forehead of the bird. When planted 10 cm apart, and 2-3 cm deep. used as a backdrop planting to a wide the bird visits the flowers on another Like all deciduous, winter-growing herbaceous border, and is particularly plant, pollen from its forehead rubs cormous plants, the corms of effective in such positions when inter­ off onto the branched stigma above, Chasmanthe are stimulated into active planted with the tall-growing winter­ and fertilization takes place. growth after their long summer flowering forms of Kniphofia uvaria. Another avian vi.sitor to the flowers dormancy by cooler night tempera­ Chasmanthe floribunda var. duekittii, of Chasmsanthe is the Cape white­ tures in late summer and early the bright primrose-yellow form, is eye, a small olive-green bird with autumn. Active growth is indicated just as easily grown as the orange one, conspicuous white rims around the first by the development of new roots, and both flower best when grown in eyes, which lives in flocks and is very followed shortly afterwards by leaf full sun. However, like C. aethiopica, common in suburban gardens in the shoots. Chasmanthe corms are so mature plants of this species do not western, southern and Eastern Cape. resilient that hardly any artificial flower every single year, so that a These cunning little birds, with a watering is necessary in the winter large number of corms are required in liking for nectar but whose beaks are rainfall region of South Africa, but in order to create a really good flowering

110 Veld &- Flora September 2001 effect. Trials in the Netherlands are seed, as well as forming offsets and that's if this has not already currently being conducted with division of the mother corm. The dark happened! A garden hybrid belonging C. floribunda var. duckittii to red and yellow flowers have striking to the closely related genus determine exactly which factors bright green markings that are ideal Crocosmia, known as Crocosmia x influence flower formation, in order to for mass planting towards the middle crocosmiiflora (previously widely make this plant a commercially viable of a herbaceous border. Its free­ known as Montbretia) has already flower bulb crop. C. floribunda is the flowering nature makes it suitable for escaped and established itself in toughest of the three species, and cultivation in deep containers with a Australia and in many other easily survives garden irrigation diameter of 30 or 35 cm. Potted countries, including Bolivia and during its summer dormant period. flowering specimens will remain in Brasil, where it is now firmly estab­ The much less well-known flower for up to three or four weeks if lished along cloud forest verges. ® Chasmanthe bicolor has for too long kept well watered. Its corms are not been neglected by-gardeners, and in quite as resilient to garden irrigation my view it is the most desirable of the during its summer dormant time as three species. Its most important the other two species, and are best Further reading attribute is that mature corms flower planted in an area not heavily De Vos, M.P. 1985. Revision of the South African genus Chasmanthe (). irrigated during the summer. reliably every single year, unlike those South African Journal ofBotany 51(4). of C. aethiopica and C. floribunda. It A word of caution to bulb enthu­ 252-261. can be grown equally successfully in siasts in Australia - the genus Duncan, G.D. 1989. Chasmanthe. In: Du both partial shade or full sun, and the Chasmanthe thrives in that country, Plessis, N. & Duncan, G.D., Bulbous plants plant produces copious amounts of and it could be potentially invasive, ofsouthern Africa. Tafelberg, Cape Town.

PROPAGATION OF CHASMANTHE

hasmanthe is one of the easiest on the mother corm, and Cirids to propagate, either by seed to a lesser extent, also or by offsets. The hard, rounded seeds propagate by division of are about the size of a small pea, and the mother corm. C. flori­ are ready to be harvested once the bunda also occasionally capsules have started to turn pale propagates by the brown and split open, revealing the formation of horizontal bright to dull orange or reddish­ stolons which develop into maroon seeds, which should be stored new corms at their tips. for the summer before sowing in A mature corm can produce autumn. Seeds can be kept at room up to five daughter corms temperature for up to a year, or in the per growing season, so that vegetable compartment of a fridge if after four years of the seeds are to be stored for sowing in remaining in the same several years time. Sow the seeds in position, a large clump of autumn (mid-April to May in the corms will have formed. Southern Hemisphere) after cool Large clumps of weather has definitely set in, at a Chasmanthe need to be depth of 3-5 mni, in deep seedtrays, lifted and divided every pots or seedbeds, filled with a well­ three to four years as the drained medium (equal parts of river­ clumps become too thick sand or silica sand and finely sifted and flowering performance compost). Choose a position in light tends to diminish markedly shade, and keep moist by thoroughly with C. aethiopica and watering with a fine rose every two to C. floribunda. The dormant three days. Fresh seed germinates corms can be lifted at any readily within three to four weeks, but time during the summer or be sure to scatter the seed evenly and early autumn months, up thinly, as sowing too thickly causes until the middle of March seedlings to 'bunch' together and in the Southern Hemi­ Chasmanthe floribunda. Photo: G. Duncan. favours the development of damping­ sphere. Use a large garden fork to lift off fungi like Pythium, especially after the clumps, then separate the offsets, watering. It is always preferable to remove and discard the 'stacks' of old water seedlings of bulbous species corms which have remained under­ SOURCES OF SUPPLY during the morning, as this allows neath the newest mature corm, and Corms and seeds of Chasmanthe them to dry off during the rest of the either replant the corms or store them are seldom available from day, leaving the leaves dry at night and in a cool dry place until planting time. commercial nurseries or redllcing the risk of attack by Be sure to dust loose corms during the specialist bulb nurseries in South damping-off fungi. The seeds can also storage period with Bexadust to Africa, but seeds of all three be dusted with a fungicide like Thiram discourage the development of mealy species, including Chasmanthe or Thiulin prior to sowing. Under bugs that thrive in the enclosed floribunda var.duckittii are ideal conditions, C. aethiopica and atmosphere of storage racks or paper regularly available from the C. bicolor can be brought to flowering packets. Kirstenbosch seed catalogue, stage during their second season of In general, Chasmanthe is pest and either free to members of the growth, but C. floribunda usually disease free during the growing period Botanical Society, or for sale flowers in its third year from seed. with the possible occasional attack by when stocks are available. Corms All three Chasmanthe species aphids to the flower buds, which are of Chasmanthe are periodically readily develop offsets (daughter usually made short work of by Cape available at the Botanical corms) produced from axillary buds white-eyes. Society's annual Garden Fair.

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