• ISSN 0140-786X

THE JOURNAL OF THE INTERNATIONAL ASCLEPIAD SOCIETY FOUNDER-A.WOODWARD

ontents May 1992 I Editorial 3

Society Matters 3

A insigniflora that isn't 6 Martin Land

Ceropegia Meyeri 7 Peter Pons

Ceropegia Ampliata - A look inside 8 Phil Clark

Letters to the Editor 1 O

Asclepiads in the Literature 13 compiled by Colin Walker

A Note on the Carallumas of Jordan 17 Colin Walker

Sultry and Seductive Stranger 20 Tim Longville

A Word about Names 20 Phil Clark

N.E.Brown's reminiscences on Stapelleae Geoff Hedgecock 21

Catalogues Received 23

Growth Forms of Ceropegia 24 Phil Clark Cover illustration: A - F Marsdenia praestans Schltr., G - N M. glabra Schltr., O - T M. kempteriana Schltr. from R. Shlechter, Die Asclepiadeceen von Deutch-Neu-Guinea (Botanish Jahrbucher 50 p. 148. 1914)

Published by the International Asclepiad Society three times per subscription year.

~ The International Asclepiad Society and the Authors of Individual articles. 1992. All enquiries to be addressed to the Editor. Subscription - £10.00 per annum - year commences 1st May

II INTERNATIONAL Asclepiad SOCIETY II OFFICIAL 1991/2

CHAIRMAN Philip E. Downs, 77 Chartwell Avenue, Wingerworth, Chesterfield, S42 6SR.

SECRETARY L.B.Delderfield, 2 Keymer Court, Burgess Hill, West Sussex, RH15 0AA.

TREASURER G.A.Hedgecock, 1 Aster Road, Haydock, St Helens, Merseyside, WA11 0NX.

EDITOR P.S.Clark, Ty Cano!, Plas Teg, Llandegla, Wrecsam, Clwyd, LL11 3AO.

SEED BANK SECRETARY R.P.Knowles, 26 Arbury Avenue, Blackbrook, St Helens, Merseyside, WA11 9HW.

PLANT EXCHANGE P.W.Noble, 21 Caernarvon Drive, Barnburgh, Doncaster, South Yorkshire, DN5 7HF (Tel: 0709 895895)

PLANT BANK SECRETARY P.Bent. 7 Bandon Rise, Wallington, Surrey SM6 8PT(Tel: 081-647 9256)

LIBRARIAN A.Kroesen, Kethelweg 21 , 3135 GB Vlaardingen, The Netherlands

SLIDE BANK SECRETARY Ors. W. Bosma, Froukemaheerd 105, 9735RH Gronongen, The Netherlands

PUBLICITY & ROBINS P.S.Clark, Ty Cano!, Plas Teg, Llandegla, Wrecsam, Clwyd, LL 11 3AO

COMMITTEE J;Thompson

AMERICAN REPRESENTATIVE D.Craig, 67 Hill Street, Norwood, MA 02062, U.S.A.

AUSTRALIAN REPRESENTATIVE P.I.Forster, P.O.Box 725, lndooroopllly 4068, Queensland,

DUTCH/BELGIAN REPRESENTATIVE P.Pons, Frissenstein 111, 1102 AP Amsterdam, The Netherlands(Tel: 020-6958084)

FRENCH REPRESENTATIVE Mrs D.M .Nelson. Passe Renard, Averon- Bergelle, 32290 Aignan, France

ITALIAN REPRESENTATIVE P.D'Annibale, Via A Bongiorno 2A/20, 00155 Roma, Italy

SOUTH AFRICAN REPRESENTATIVE P.R.Alp, C/O Northam Platinum Mine, P.O.Box 441, Thabazimbi, 0380, R.S.A.

ZIMBABWEAN REPRESENTATIVE N.Hughes, 10 Garry Owen Way, Riverside, Bulawayo, Zimbabwe EDITORIAL

In view of Ken Harold's resignation, I am editing Asklepios for the time being. Ken's skills, botanical, graphical and editorial can be seen in the way which the presentation of Asklepios has developed over his period of editorship. I hope that Asklepios will continue to perform its' function as the only international journal devoted to Asclepiadaceae.

Every Editor makes pleas for more material to publish · this one ls no exception! Past numbers of Asklepios contain articles of all kinds related to the Asclepiadaceae, it is anticipated that this breadth of cover will continue. Personal comments, as well as more serious botanical articles can often be valuable in filling gaps in our experience. The dicussion concerning Huernia continues. In a note about Asclepias syriaca questions are raised about Asclepias from a horticultural point of view. However there are other aspects - I gather that a few Asclepias spp. are serious weeds in some parts of the world. Further comment on these topics would be of interest. In general, it makes good reading to have a varied selection of articles made up from contributions from people with different interests.

I have been somewhat taken aback, during correspondence about the Robin, by the depth of feeling between Hoya groups - a little has spilled over into this journal. For those like myself who are unfamiliar with the Hoya world, it appears that there are are two rival Hoya societies in the U.S.A. As collectors grow because they like them and are interested in them, it would be most unfortunate if these rivalries crossed the Atlantic (or Pacific). There is mt,Jch to be gained from constructive controversy, little from animosity.

For those In the Northern Hemisphere, I hope that you have a good season ahead. For those in other parts of the world, I hope that your plants will have a peaceful rest after a successful season. SOCIETY MATTERS SUBSCRIPTIONS

A subscription form is included with this issue. Please could all members renew now, even though you may have done so at a different time before. It is a great help to the Society if you pay promptly, and it reduce the chance of the subscription being forgotten. Only paid up members will receive the August edition of Asklepios. Unfortunately it is too expensive to send out reminders.

Asklepios is the major expenditure born by the Society. We have adopted a policy of including a page of colour whenever possible. Though this is much appreciated, it does increase production costs. As we have no wish to increase subscriptions, it would be most helpful if members, who feel that they are able, would be willing to make an additional donation to assist in covering costs.

U.K. ASCLEPIAD VISITS

These will take place on Sunday, 13th September 1992. Keith Grantham has kindly agreed to let us see his collection. East Midland Nursery and Woodside Nurseries are within reach, so these are included in the programme. In addition to the Asclepiad interest. these meetings are pleasant social occasions. For details, write to Phil Clark (Address on inside front cover). DUTCH/BELGIAN ASCLEPIA DAY

On Saturday June 6th 1992 the Belgian and Dutch members of the IAS will be having their 7th annual meeting, the well known Asclepia Day.This year the event will be organised by Belgian members and will take place in DOMEIN DE LOCHT, LIERSESTEENWEG, 2570 DUFFEL (near Antwerp) BELG IUM. Program: (Lectures will be in Dutch) 10.00 Doors open 10.30 Opening and lecture by Louis Van De Meuter : and of the Asclepiadaceae. 11 . 15 Coffee break 11.30 Lecture by Maurice Genotte: The Ceropegia 12.30 Lunchtime. Tea/coffee and cold drinks will be available. Before and between lectures there is room for selling or exchanging plants and cuttings. In the afternoon there will be an opportunity to visit the collections of several members in the neighbourhood. Addresses and maps are available at the meeting. The Asclepia Day is open to anyone interested in Asclepiadaceae, but if you want to take part in the event. please write to:Mr G Cools, Adrinkhovenlaan 107, B-2150 Borsbeek, Belgium.

1993 ASCLEPIAD WORKSHOP

Peter Bent will be hosting the 1993 Asclepiad Workshop. It is still at an early stage of planning, but an interesting programme is anticipated. It will take place during the the first half of September 1993. It you would like to take an active part, or have any ideas about the kind of activities that you would like, please contact Phil Clark. This is an early notice so that any items of particular interest can be put into the programme.

PLANT BANK

Progress has been rather slow. It is taking more time than was anticipated to build up stocks again. Unfortunately. choice plants reproduce themselves slowly - which is one reason why they are choice! The aim of the Plant Bank is to be able to offer authenticated material, new introductions, difficult and so on. The Plant Bank does still need stock plants, so if you have anything interesting to spare, please let Peter Bent know - address and phone no.

PLANTEX The First Annual Report on tbe Plant Exchange Scheme

Although the scheme should now be known to all who read Asklepios, the response has been less than expected, only six names adorn the Plantex file at this time and this seems to suggest that everyone has all the plant material that they need, but I cannot believe that this is the case. One member has over a hundred documented specimens from twentysix genera for exchange or purchase, another offers seedling plants from habitat collected seed of Huernia and (few only) and cuts of Duva/ia ve/utina with a very striking . The aforementioned are in very limited quantity but the diversity is manifold, so why not test the menu, by contacting the The Plant Exchange Secretary by mail or phone (see address on inside front cover).

ROBINS Ceropegia Robin:

Due to the success of the Ceropegia Robin it has been divided into two halves, but arranged so that each wi ll see the writings of the other half. In this way it is hoped that the circuit will be shortened without inhibiting communication.

H oycr Robin: This has now been launched. Paul Forster is now coordinating this, so please point all enquiries in his direction :P.1.Forster, P.O.Box 725, lndooroopilly 4068. Queensland. Australia.

Key to colour plates Fig.1 Huernia insignif/ora (formerly H. confusa) Fig. 2 H. insigniflora Lavranos 26227 Fig.3 H. insigniflora ex. I AS. Plant Bank No. 11 Fig.4 H. zebrina I.A.S. Plant Bank No. 16 Fig.5 H. zebrina subsp. magniflora Figs. 6&7 Ceropegia meyeri Fig.8 Ceropegia ampliata: PRA 6 clone4: cultivated clone; PRA6 clone 3 Fig.9 C. amp/iata: cultivated clone. approx 7cm long. Fig.1 O C. ampliata: sectioned flowers from fig.8 Figs.1-5: cult & photo-Martin Land. Figs. 6&7: cult-Peter Pons: photo-Wiebe Bosma. Figs.8-10: cult & photo-Phil Clark. 2

3 5

6 7

8 9 10 Chatline Robin:

A proposal for this was outlined by John Spearing in No. 54. This is a good opportunity for long-distance correspondance about any aspect of Asclepiad interest to the writer - and subsequently also of interest to other members in this Robin circuit. Please contact Phil Clark if you are interested - it only takes a few willing participants before it takes off. 8.C.S.S. NATIONAL SHOW-22 A VG 1992

We have a skeleton staff of stewards for the I.A.S. Stand at this show but a few additional helpers wouild be most welcome. It would also be nice to have a few plants to display - if anyone can bring something along, showy but not valuable, it would add interest for the general public. Please regard the I .A.S. stand as a meeting place for members - we will look forward to seeing you there.For details contact Phil Clark after the beginning of August.

FROM THE EDITOR

If you have read so far you will have gathered that I am editing Asclepios for the time being! An enjoyable but very time consuming task. So that things will run smoothly, it is hoped to build a small team concerned with the production of Asklepios. One vital member is Martin Smith, who is putting the copy into a format suitable for the printers.

Articles in any format are welcome, handwritten or typed. However if you have access to a computer it would be most helpful if you could supply your work on disk. Anyone wishing to do this should contact Martin Smith directly on 071-639 4566 before putting it in the post. Thanks, Phil Clark.

Can you help'l Qequest for Hoya curtisii and H.pruinosa. I should be grateful to hear from anyone who may be able to supply a cutting of either of these plants. An exchange of Hoya material may also be possible. Please contact: Kevin Mann - Broad Cottage, lrstead, Norwich, Norfolk, NR12 8XT

I.A.S. Publications Back numbers of Asklepios and Asclepiadaceae The following issues are available from the Secretary, Les Delderfield: Asclepiadaceae 12-21; Asklepios 23-30, 33-34, and 42-48 Price £3 each.51 is available for £4. 50 and 52 include colour pages and are £5 each. Please make cheques payable to the International Asclepiad Society. The Checklist and literature list of the .

The Checklist and literature list was published in 1987, runs to 185 pages, and covers most genera and species of the Stapeliae, including Ceropegia, and . A separate supplementary volume has been published.

The checklist is available from Les Delderfield, price £6.50 inc. postage. Please make cheques payable to the International Asc/epiad Society.

The 1990 Supplement is also available from Les Delderfield.Price: £3 inc. p & p., comb bound.

And finally thanks to: Kevin Mann and Geoff Hedgecock who have agreed to proof-read Asklepios, including this issue. Any residual errors and inconsistencies are mine. ~ pt.J~

ASKLe:1>1os s A HUERNIA INSIGNIFLORA THAT ISN'T By Martin Land, with photographs by the Author.

Summary: Details are given for an aberrant form of Huemia insigniflora C.A.Maass. The plant possesses a corona with margined outer lobes and in this respect disagrees with the species description by Leach ( 1988).

In the summer of 1991 I was most fortunate in being able to observe the flower of a particularly pretty example of Huernia insigniflora, a plant obtained from Whitestone Gardens Ltd. with the collection no. Lavranos 26227. Besides being a delight to view, this Lavranos insigniflora is notable in that it defies Leach's recent description for the species in one conspicuous way, of which I will say more later.

I have flowered one other clone of H. lnsigniflora s.s. , a plant distributed by the I.A.S. Plant Bank (No. 11 ), which appeared to represent a more typical form. (Plants with blotched or striped corolla lobes that formerly bore the name H. confusa Phillips are now included in this taxon.)

A brief discussion of the salient features of this plant will act as an introduction to the species for readers, H. lnsigniflora bears flowers of the lifebouy type, the corolla is thickened and strongly convex forming a shiny annulus that encircles the corolla tube. In the I.A.S. insigniflora clone the annulus is coloured bright crimson red; the Lavranos form is dull maroon (Leach gives a colour range from pale crimson to deep purple or brown). Five pale, creamy yellow corolla lobes lie beyond the annulus. These are deltoid (triangular) in shape and typically as wide or wider than long. Evenly distributed over the face of the corolla lobes are minute red papillae, each tipped by a short, sharply pointed hair cell. In the Lavranos insigniflora particularly, the papillae impart a sort of pinkish bloom that is most appealing to the eye. The outer lobes of the corona, to be found at the base of the corolla tube, are a dark shade in the I.A.S. plant. Leach states that they can be either dark or pale coloured with cream to buff shades most commonly met with.

In most respects the Lavranos insigniflora conforms with the species description given by Leach, although its blooms are rather large at 38mm in diameter ( a range of 25 - 36 mm is given by Leach, the 4 - 4.5 cm quoted in White and Sloane (1937) from the original description by Herr Maass seems somewhat fanciful!) Most interesting and of possible significance, is the character of the Lavranos plant's corona. Leach stresses that in this species the outer lobes at the corona never possess a dark margin and yet in the Lavranos form these lobes are pale and do display a prominent purple border - in very much the same fashion exhibited by insigniflora's closest relation, H.zebrina N.E.Brown. During the summer of 1991 my plants of the Lavranos clone produced several flowers, all alike in this respect. Leach lists the absence of a dark margin as a characteristic by which insigniflora may be distinguished from zebrina. Indeed Leach seems to consider this character as diagnostically important. While the dark margin of the Lavranos insigniflora's outer corona may create difficulties in identification, its' presence certainly makes a significant contribution to the beauty of the flowers of this problematic clone.I suppose this insigniflora plant demonstrates just how difficult is the job of laying down the rules by which plant taxa are identified and segregated. The variation encountered among Stapeliad species is such that one may come to wonder whether any any sing le apparently constant characteristic can really be relied upon on its own. These days, as is the case with Leach's Huernia monograph, plants are assessed using a variety of both floral and vegetative characteristics in conjunction. This was rarely so prior to about the 1970's when the classification of Stapeliads was principallly based on floral and on particular coronal characteristics. This approach led to the establishment of all sorts of inconsistencies in the naming of Stapeliads - a nomenclatural minefield that has needed much work over the last decade to attempt to unravel. Even as recently as 1990 there existed such obviously erroneous names as Stultitia araysiana Lavranos & Bilaidi. (This plant was placed in this genus on account of its ascending connivent inner corolla lobes and annular corolla swelling). This wonderful Stapeliad from the now has the epithet araysianum (Lavranos & Bil aid I) M. Gilbert, being transferred to that genus along with the plants that had previously been known as the Ango group of of Qarallumas of which S.araysiana was such a typical member.

One can only sympathise with the workers who specialise in the Stapelieae field. Stapeliads typically exhibit great morphological variation, with such variation representing a gradation of form between species. In the latter instance the status of allied plants may be especially difficult to determine. Another problem is that some species are still only known from descriptions of a single or a small number of plant specimens. For these the overall level of variation must remain unclear. No wonder that some Stapeliad plants are liable to defy human efforts to see them packaged into neat biological units.

List of measurment records for each of the five plants illustrated: Huernia insigniflora Lavranos 26227 Corolla diameter : 38 mm Corolla lobes: 10mm long x 13mm wide Pedicel length: 7mm Calyx lobes: 7mm long x 1,5mm wide

H. insigniflora I.A.S. Plant bank no. 11 Corolla diameter: 25mm Corolla lobes: 7mm long x 10.5mm wide Pedicel length: 9mm Calyx lobes: 6mm long

H. insigniflora (formerly known as H. confusa) Corolla diameter: 30mm Corolla lobes: 7mm long x 12mm wide Pedicel length: 10mm Calyx lobes: 4mm long x 2mm wide

H. zebrina I.A.S. Plant bank no. 16 Corolla diameter: 40mm Corolla lobes: 11 mm long x 15mm wide Pedicel length: 10mm Calyx lobes: 6mm long x 2.5mm wide

H. zebrina subsp. magniflora Corolla diameter: 59mm Corolla lobes: 15mm long x 22mm wide Annulus height: 8mm Pedicel length: 8mm Calyx lobes: 9mm long x 2.5mm wide

References Gilbert,M.G. (1990) A review of R.Br. and its segregates.Bradleya 8 p. 1 - 32 Lavranos,J.J. and A.S.Bilaidi (1971) Notes on the succulent flora of North East and Southern Arabia, Part Ill Cact, Succ, J. (U.S.) 43 p. 204-208 Leach, L.C. (1988) A revision of Huernia R.Br. (Asclepiadaceae). Excelsa Tax. Ser. No. 4. White, A. & Sloane, B.L. (1937) The Stapeleae Abbey San Encino Press, Pasadena, California.

CEROPEGIA MEYER! by Peter Por,,s

This species was, until recently, only known to me from the beautiful drawings in R.A.Dyer's books (1980/1983). In April 1991 I acquired a specimen in Ernest Specks' nursery Exotica in Erkelenz-Golkrath; a small tuber with a depressed top surface. Tl1e tuber was indeed dark brown, with a rough bark-like exterior, as stated by Bruyns (1984).

At home I repotted it in my own mixture, consisting of 50% compost, 50% coarse sand and baked clay granules. Soon it started growing vigorously, and at the end of June the first flowers opened. Flowering didn't stop until the end of October, with a short interval in August when I cut it back to take some cuttings for propagation. In October water was gradually withheld, and the shoots died back to ground level.

The tuber, which has grown 4 or 5 times as big as when I obtained it, was kept completely dry over winter.When in growth Ceropegia Meyeri seems to need plenty of water. If the soil is allowed to dry its large, non-succulent will soon start to droop. At first I kept it in a south-west facing window, but it didn't appreciate the full sunshine it received there. Its first buds aborted. So I moved it to an east facing window, where it fared much better, receiving only early morning sunshine. this more or less reflects its natural habitat: in the wild C. meyeri prefers the shade of scrub-bush or scattered trees. (Dyer 1983, Bruyns 1985).

Propagation of Ceropegia meyeri is quite easy. Immediately after taking them the cutting were placed in a small container on a heated bed, under plastic as its stems and leaves are non-succulent. The cuttings rooted quickly and started growing soon after. Unfortunately they did not survive my move from Groningen to Amsterdam in September, which brought many more losses.

The flowers of C. meyerifully live up to their promise: they are ca. 4cm long and very handsome (see photograph by Wiebe Bosma). Unfortunately they are very short lived. They hardly survive for more that one day. Ceropegia meyeri occurs in (East-Cape, Natal, Transvaal), Mozambique, Zimbabwe, Zambia and Namibia. It was discovered by Drege in the Transkei in 1832 and described (by Decaisne in DC .. Prodr. 8: 645) in 1844. Despite the large area that the species covers the flowers are very uniform, whereas the leaves are quite variable. They were described as elongated cordate-ovate, with the margins entire, but in South Africa (Cape) plants with indented or even lobed leaves grow together with plants with entire leaves. (Bruyns 1985).The species stands out for its bottle shaped flowers, so unique in shape within the genus that it cannot be mistaken for any I hing else. Its closest relative seems to be Ceropegia bonatouxii. Bruyns (1984) even suggests that C. meyeri and C. bonatouxiimight represent one widely distributed, variable species. Whether they are conspecific or not, their hairy, non-succulent stems arising from a tuber, and their hairy non­ succulent leaves wh ich resemble climbing species of Convolulaceae or Cucurbitaceae, clearly set them apart form all other species in southern Africa.

References: P.V Bruyns (1984) Ceropegia, Brachystelma and Tenaris in S.W. Africa Dinteria 17, p. 17-83 (1985) Notes on Ceropegias in the Cape Province. Bradleya 3, p. 1-47 A.A.Dyer (1980) Asclepiadaceae. Flora of Southern Africa, vol.27(4). (1983) Ceropegia, Brachystelma and Riocreuxia in Southern Africa A.A.Balkema, Rotterdam. H.Huber (1957) Revision der Gattung Ceropegia. Mem. Soc. Brot. 12, p. 1-203.

CEROPEGIA AMPLIATA - A LOOK INSIDE by Phil Clark

Ceropegia ampliata is widely distributed up the eastern side of the African continent, from Cape Province to the tropics and . The typical habitat is dry scrub, the shoots climbing up, through and over the bushes. The rather thin perennial semi-succulent stems are very inconspicuous when it is out of flower. However when in flower, the large pale green flowers conspicuously decorate the bush up which it has climbed. In cultivation the flowers occur late in the season, often durng September and October in the U.K.

In the greenhouse it is a vigorous and often very floriferous climber (Fig.9). It is also relatively easy to grow and flower, which helps to account for its popularity. Like other species with fusiform roots, it does not like wet feet in the winter - large plants are better in clay pots. On the other hand, it will take a reasonable amount of water while growing. It appears to appreciate more light than most species, but not full sunlight.

Like many Ceropegias, C. ampliata is very variable, some of this variability being seen in Figs. 8 and 10. Small are attracted to the newly opened flower, probably by scent. They cannot settle on the slide zone - the smooth part of the upper part of the corolla tube, so they tend to descend to the bottom. It is likely that the dark region is attractive to these flies (also found in C. haygarthii, C

Ma_(: or f/ne ha.i'rs p-,1eve-nl:s Cvl: s/::o../J.< tJsca.pe or f./i°(!S u-nl:,'/ the ~{:- ba.~(' / h0t.i7'S co//a.fSP of f-lo ""e..,,,

/7,yeJ v!Cl.-Y "ul:li-ne f:-o -re.cl. b~,nd

Basa.I inF/e<.t,-o""' - ho-me to /:-rapped Flies u-,,f:,'/ -,~/ea.sed

C.ampliata PRA6 clone 3 - section thr©ugh flower

Cvl:: coyo//o.. ® From base 0 f f / 0 1,.,/ l'-Y

Clone 1 Clone 4

'i'wo clones of C.ampliata PRA6 showing Drawn from photographs differences in the devel0pment of the cage by Phil Clark C. linearis ssp. woodii and a number of other species). Once trapped, flies aim for the light rather than the dark, but escape is prevented by the hairs. The paleness of the basal inflation distracts their attention from the hairs above (some species have translucent 'windows' for the same reason). A~er a period of time, the hairs collapse, allowing the flies to escape. During their imprisonment. the flies will have either deposited or collected pollinia. Fortunately for the Ceropegia, flies do not learn from the experience, being trapped by more than one flower, enabling cross pollination to occur.

Apart from the difference in size, the red band at the base of the corolla tube is absent in the cultivated clone. In other clones (not illustrated) , the proportions of the flower differ also. One can speculate that these differences may be related to the pollinators. After all, if Ceropegia flowers of the same species are variable, would it not be logical to expect the same of the ? The usual reason for taking a flower apart is to look at the corona, but the hidden architecture of the corolla tube is also worth examination. Next season, if you can bear to do so, section flowers to look at the insides. There are all kinds of strategies employed to trap and retain flies before release. In order to acheive this, flowers subtley change from opening until wilting. This can add a further dimension to an interest in the form of the flowers.

References: Bayer,M.B. (1978) Pollination in Ceropegia ampliata E. Meyer. Asclepiadaceae 14 p.17-18 Bruyns,P.V. (1985) Notes on Ceropegias of the Cape Province. Bradleya 3 p.1-47 Harold,K. (1985) Ceropegia ampliata (E.Meyer). The Xerophyte 8 (2) p.39-41 Acknowledgements: Thanks to Philip Alp and Martin Land for supplying the clones illustrated.

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Lette~s to the Edito~ Dear Sir,

In the paper by Shiela Collenette on 'Ceropegias in Saudi Arabia', I note that 'Group 4', the arabica group, is characterised as having greyish stems, although I have two collections with distinctly yellowish-green stems, the colour being maintained in maturity. The stems of both collections are slightly ridged. I refer to C. arabica FKAN 2009, from the Yemen, and to another collection received from David Cumming from Wadi al Uss, which appears identical in cultivation here. These plants most closely identify with C. arabica var. abbreviata. Just occasionally the corolla lobes of some of their flowers partially open and I Initially thought that this was a distinguishing feature between the two collections. Subsequent observation confirmed its occasioal occurence on both plants. Last September, a pair of seed horns rapidly developed on arabica FKAN 2009 and each is now 140 mm long. These have a sheen to their surface, and are bright mid-green, and so less yellowish green than the stem colour. The seed horns have remained unopened until the time of writing (late March).

These two plants are among the most free flowering ceropegias that I have. I have received arabica FKAN 2009 with the information 'green flower', although I would have described the corolla lobes as yellowish rather than green. I also received another Noltee collection of arabica, FKAN 1825 with ·yellow flower' on the label, but unfortunately the latter did not establish, and so I was unable to see how the yellow flower compared with the one considered to be green.I would be pleased to send material of these attractive ceropegias to anyone interested In either of them, whether in this country or abroad, and if you have yourself any Ceropegias relating to the arabica group with yellowish-green stems, I would appreciate material to compare with the plants here.

Kevin Mann - Broad Cottage, lrstead, Norwich, Norfolk, NR12 8XT.

Dear Sir,

May I respond to Leach's reply (Asklepios 52: 83-5) to Meve's review (Asklepios 48: 57-8) of Excelsa Taxonomic Series 4. I personally felt that Meve's comments were extremely fair and that there were an inordinate number of trivial errors in this volume, as in No. 3. However, these do not

ASK1.C1>JOS 10 affect the taxonomy. Relevant to the taxonomy are two fundamental problems which have not been resolved. One of these lies in the classification of the species into sections and series.

It is impossible to classify satisfactorily any assortment of species by merely picking out the obviously matching elements and by this manner working through the group from one end to the other. The result of such a procedure invariably is a residue of species which do not fit satisfactorily into any of the groups. What then can be done with this residue? Clearly one is compelled to begin the process again by modifying the sections so as to fit the anomalous species in as far as possible.

This problem is not by any means confined to the Asclepiadaceae, as most families and genera consist of elements that are well defined and elements which are not. However the classification of the Stapeliae has repeatedly produced such residuesof ill-fitting species. There is the dustbin genus Caralluma, which was clearly problematic even long before White & Sloane's classic work appeared, and it remains so today. The more recently resurrected is a similar case where three quite unrelated species have been placed together largely because they will not fit readily into any of the already-worked-out genera without diluting the the apparently neat definitions of these genera. Precisely this problem now occurs in Huernia In the section Fa!lacistelma. The introductory paragraph to this section (page 161) reads: Although perhaps appearing .... to be an ill-assorted group, an impression that is heightened by the absence of an overall key-character, it seems that the species of this section are nevertheless more closely related to each other than to any other of the recognised groupings. In his reply to Meve, Leach emphasises that our taxonomy must be based on observable facts . What are the observable facts here? What evidence is there that these species are nevertheless more closely related to each other? Is it because they share the character that they don't relate to anything else?

I would in fact go further and suggest that Huernia cannot be partitioned as neatly into Sections and

The second, unresolved, fundamental problem is the concept of species. There are actually two problems here:

(1) Has a concept of species in Huernia (or the Stapelieae generally) been elucidated?

Individuals grouped into a species should occur in one or more populations whose geographical arrangement constitutes the distribution of the species. Within this distribution there should be continuity in variation. Between individuals grouped into one species and those included in related species there should be discontinuities in the pattern of variation, i.e. the distinct species must be discrete elements.

Nowhere does Leact1 discuss what he reasons should constitute a species and it is my impression that the many species recognised in Huernia do not satisfy these elementary criteria.

For example, while the long-standing nomenclatural confusion surrounding Huerna concinna is admirably sorted out, further taxonomic confusion

Similar problems arise with H. bayeri. The discussion on pag 189 suggests that the situation is highly confusing. In Bayer's own experience (pers. comm .) this species does not form a recognisable taxon in terms of geographical distribution, variability across the range and discontinuity witl, other elements. There is in fact a herbarium sheet of Leach & Bayliss 15677 B at BOL as well. The photograph on this sheet does not bear any resemblance to Fig 123 but looks just like Fig. 107 with flowers that are not at all campanulate as they are supposed to be.

The treatment of H. scabra var. ecornuta too is most peculiar. It is considered probably to be of hybrid origin and H. praestans is suggested as a parent (pp. 166, 191 ). However the type (Pillans 55) is from north-east of Beaufort West and H. praestans (according to Leach) occurs on ly on the Little Karoo south of Laingsburg. I have found this taxon atr the type locality and there seemed to be no evidence of hybridisation. It would seem that this hybrid explanation is being used to cover up some measure of confusion or explain away variation which does not fit into the extremely variable Huernia brevirostris. This appears to indicate an underlying reluctance to accept and admit that some parts of the genus cannot be partitioned rigidly into a microspecies and a reluctance to broaden t he species concept to fit the facts, i.e. to fit the remarkable degree of variation that is present in some of these elements.

This brings one other problem.

(2) Is the species concept, if any, consistent with that used in the past?

There appear for example to be greater differences in BOTH the coronal structure AND the stem morphology [both charqacters used extensively to separate species of HuerniaJ between Orbelj;psis gerstneri subsp. gerstneri and 0. gerstneri subsp. elongata (Leach in Excelsa Tax. Ser. 1, 1978) than there are between any of the three species of Series Cleisostelma or even the whole section Fallacistelma. While it is extremely difficult to achieve consistency across groups this is nevertheless a desirable goal and one which does not appear to have been reached here.

One has, at the end, to ask whether the position of Huernia has improved. To this the answer is surely yes. However, no revision is ever the final word on a genus and in view of the above it is clear that Huernia (and indeed the whole classification of the Stapeliae) is going to have to be revised again now that Leach has begun the process of clarifying what the elements probably are.

P.V.Bruyns

Dear Sir,

I'm a botanist in Moscow State University at Department of Higher Plants, where I'm studying phylogeny and systematics of Magnoliophyta on the base of evolution of its seeds, and seed coats in particular. Being very interested in the origin and systematic placement of Asclepiadaceae and , I should like to ask you and the members of your society to help me in obtaining of seeds and possibly of these families. I shall be very grateful if you and and your members might support our studies leading to the concretisation of phylogeny and systematics of both taxa. Alexander B. Doweld A.B.D. U1. Matveyvevskya, 32-144 RF-119517, Moscow, G-517 Russia Editors note: I hope that someone can respond to this request. it would be nice to feel that we are able to help in this way. Asclepiads in the Literature Compiled by Colin C. Walker Thanks go to Paul Forster, Gordon Rowley and Jeff Ollerton for assistance with the compilation of this column, without which coverage would be very incomplete. Many thanks also to the authors who kindly supplied reprints of their papers, either unsolicited or on request. I would be most grateful if authors would please continue submitting copies of publications for inclusion. Notification of omissions of recent work would also be appreciated. Again a single alphabetical list of publications is provided for easier reference, with comments provided as previously for papers and articles thought to be of particular interest to our readers. Unfortunately in this column in the last issue of Asklepios (No.54) two items became merged into one, making a nonsense of them. These items (Nos.15 and 16) are included again to avoid any confusion caused last time around. (1) Aloe, 28 (2), 1991. A variety of articles discuss and illustrate asclepiads. Clive McDowell in 'Pests, diseases a'ld their control' (pp.42-51) describes the various pests and diseases that befall succulents. Detailed Tables indicate relative susceptibilities of the different succulent groups, and recognition, treatment and prevention of key pests and diseases. These are the first such comprehensive listings of this kind that I have seen in print. Not surprisingly, asclepiads feature prominently amongst the succulents prone to attack. A Trichocaulon is shown in colour suffering from damping-off, whilst a is equally vividly illustrated covered in root mealy bug. Robin Frandsen (p.57) describes schinzii as "not a difficult plant in cultivation and its attractive stems and unusually large and striking flowers make the plant a fine and dramatic addition to any collection". Two habitat studies show the plant and its eye-catching flowers in colour. Robin Frandsen again, in 'Stapeliads and the Stapelieae of Baron N.J. von Jacquin' (pp.60-63) outlines some of the history of our beloved plants, emphasizing Jacquin's key role in their glorification in his wonderful colour plate book 'Stapeliarum in Horti Vindobonensis Cultarum' of 1806-12, now available as a facsimile. Six plates of historical interest (three in colour) are reprinted, together with a portrait of Jacquin. Finally, a magnificent habitat shot by Roger Dixon, shows a large flowering specimen of macrantha in glorious colour as a full page portrait on the back cover. (2) Bruyns,P. & Llnder,H.P. A revision of Mlcroloma R.Br. (Asclepiadaceae - Asclepladeae). Bot. Jahrb. Syst., 112: 453-527, 1991. The genus Microloma A.Br. is revised. Excellent introductory material covers comparative gross morphology, pollination, generic and infrageneric relationships and distribution. Ten species are recognised: M. poicilanthum Huber, M. armatum (Thunb.)Schltr. ex Gilg, M. longitubum Schltr., M. hereroense Wanntorp, M. calycinum E.Meyer, M. sagittatum (L.)R.Br., M. incanum Decne., M. penicillatum Schltr., M. namaquense H.Bolus and M. tenuifolium (L.)K.Schum. The new combination M. armatum var. burchellii (N.E.Br.)Bruyns is published. The genus is divided into four sections, two of which which are described as new. Each species is described in detail, material examined is cited and full synonymy given. For each taxon, excellent line drawings are provided to show the main features of the plant, and detailed distribution maps supplied. A cladistic analysis is provided in an attempt to establish the precise genealogical relationship among the species. As a consequence of this analysis the authors conclude that "an understanding of the phylogeny of Micro/oma can contribute significantly to our understanding of the floral history and relationships of the arid western parts of southern Africa. Although the model proposed here, with speciation driven by changes in the rainfall regimes, may be simplistic, it provides an Initial hypothesis on the influence of longterm climatic change on the flora of these areas." This revision differs significantly from that published by Wanntorp in 1988, where 19 species were recognised; the principal difference between these two conflicting revisions is that the current work is based on extensive fieldwork. (3) Dave,V. &- Kurlachen,P.M. Comparative anatomical characters of Perlplocaceae follicles and their taxonomic significance. Feddes Repert., 102: 63-8, 1991. Detailed study of the follicles of Cryptolepis buchanani and Hemidesmus indicus. The pericarp anatomy of these two genera is compared with that of Cryptostegia grandiflora and a taxonomic key is also added to delineate these genera. ( 4) Farrell,B.D. et al. Escalation of plant defense: do latex and resin canals spur plant diversification? Amer. Nat., 138: 881-900, 1991. Latex and resin canal-bearing plant groups appear to be significantly more diverse than groups without such defense strategies. The Asclepiadaceae was one of the families used to test the hypothesis. (5) Fontana,J.L. Me/In/a iberae, nueva especie de Asclepiadaceae. Falla Botanics et Geobotantca Correnteslana, 4: 1-7, 1990. Paper not seen. (6) Forster,P.I. The Identity of Toxocarpus papuanus van Royen (Asclepladaceae}. Blumea, 36: 105-8, 1991. Toxocarpus papuanus van Royen is a species of Marsdenia and is renamed as M. argentata P.Forster, for which a detailed description and illustrations are provided. (7) Forster,P.I. A taxonomic revision of Gymnanthera A.Br. (Asclepladace-ae: Periplocoldeae) In Australia. Aust. Syst. Bot., 4: 563-9, 1991. The genus Gymnanthera is revised for Australia. Two species are recognised and the relationship between them discussed. G. nitida R.Br. is widely distributed in coastal areas of tropical Australia and Malesia. G. cunninghamii comb. nov. ( Wrightia cunninghamii Benth.) has a disjunct distribution in arid central Australia. Illustrated with line drawings and a distribution map. (8) Forster,P.I. The distribution and synonymy of Tylophora biglandulosa (Asclepladaceae). Kew Bull., 46: 563-7, 1991. Tylophora biglandulosa (Endl.)F.Muell. is shown to have a wide distribution in Melanesia and Lord Howe and Norfolk Islands, and seven taxa are reduced to synonymy. Detailed description and distribution records are provided, and the species is illustrated with high quality line drawings. (9) Gandhl,R. Indian Carallumas. /SOCS Newsletter, 4: 1-5, 1991 . A very brief introduction to Indian Carallumas, followed by a complicated three page key to all the species excepting C. frerei (Frerea indica). It is written in bad English and the sources for the data used to construct the key are not given. I suspect that the key is probably too simplistic to be of any real use when one is confronted with living material of the very variable Indian Carallumas. (1 O) Goyder,D.J. & Slngh,N.P. Lectotyplflcatlon of Periploca secamone and Secamone thunbergll (Asclepladaceae). Taxon, 40: 629-630, 1991 . Periploca secamone L. and Secamone thunbergii E.Meyer, here first lectotypified, are synonyms of Secamone alpini Schultes. ( 11) Gratlas,J. Stapel/a nob Ills N.E.Br. Kaktusy, 27: 42-3, 1991 . Two large-flowered , S. nobilis and S. gigantea, are compared. Here, though, the author is somewhat out of date, since Leach (1985) considers these taxa to be conspecific. Experience with the cultivation of this species is summarised. Illustrated with three black and white photos. In Czech with brief English summary. (12) Gratlas,J. & Mitlska,L. Ceropegla clmlclodora Oberm. Kaktusy, 27: 56-8, 1991. Two species of Ceropegia, C. cimiciodora and C. stapeliiformis are compared and illustrated with black and white photos. Experiences of cultivation of these species are provided. In Czech with brief English summary. (13) Jenklns,T. Edlthcolea grandls. The Cactus File, 1: 27, 1992. E. grandis is one of the most fascinating and frustrating of all the stapeliads to grow and flower. Tom Jenkins reports on his successful method for taming this spectacularly flowered rarity. Illustrated with a colour photo. ( 14) Kahn,A.P. & Morse,D.H. Polllnlum germination and putative ovule penetration In self· and cross-pollinated common milkweed Ascleplas syrlaca. Am. Midi. Nat., 126: 61·7, 1991 . (15) Keen,W.C. Plaranthus decorus. Brit. Cact. Succ. J., 9: 27, 1991. A brief note accompanying a line drawing of P. decorus. ( 1 6) Keen, B. Vereker's Huernla. Prickly Paragraphs, 100: 38-9, 1991. A discussion of the discovery of Huernia verekeri, together with notes on the species, its varieties and cultivation, accompanied by a colour photo showing the typical form in flower. (17) Keen,B. The genus Trlchocaulon. Prickly Paragraphs, 101: 2-5, 1992. A survey ofTrichocaulon, including a look at the history of this genus and a list of the species currently included, together with an indication of their relationships. Much of the article deals with techniques of cultivation, based on the author's long experience. Illustrated with a line drawing of T. cactiforme. (18) Krapovlckas,A. & Moral,S.C. La ldentldad del genero Me II n I a (Asclepladaceae}. Darwinians, 30: 277-280, 1990. The nomenclature and taxonomy of the genus are clarified, on the basis of the type species M. candolleana (Hook. & Arn.)Decne. Eight species are accepted, and some new combinations published. In Spanish with English summary. ( 19} Kunze,H. Structure and function In ascleplad pollination. Pl. Syst. Eva/., 176: 227-253, 1991. Aspects of floral biology in relation to floral structures were investigated in seven species of asclepiad, namely Secamone alpinii, Tylophora sp., Leptadenia sp., Sisyranthus sp., Astephanus triflorus,

ASKl.C;;'PJOS 14 Microloma calycinum and officinale. Well illustrated with black and white photos and line drawings. (20) Liddle,D. The large white Hoya species of Papua/New Guinea. Fraterna, 4: 4-10, 1990. Paper not seen. (21) Liogler,A.H. Novltates Antlllanae, XVI. Phytologla, 70: 149-157, 1991 . New species and new combinations from the island of Hispaniola are published, including three new combinations in . (22) Marohasy,J. & Forster,P.I. A taxonomic revision of Cryptostegla R.Br. (Asclepladaceae: Perlplocoldeae). Aust. Syst. Bot., 4: 571-7, 1991. The genus Cryptostegia comprises two species, both of which are endemic to Madagascar. c. grandif/ora Roxb. ex A.Br. is widely naturalised in tropical regions of the world. C. madagascariensis Bojer ex Decne., comprises three varieties, of which C. madagascariensis var. glaberrima (Hochreutiner)J. Marohasy & P.Forster is a new combination, and var. septentrionalis J. Marohasy & P.Forster is newly described. lnterspecific hybrids occur in a narrow zone where the two species are sympatric. Illustrated with photos and distribution maps. (23) McDowell,C. Growing succulents under cover In South Africa. Veld & Flora, 77: 18-21, 1991. A brief introduction to the succulent asclepiads, and their cultivation in South Africa, under the following headings: growth in the natural habitat; light and temperature; water; soil; containers and transplantation; special problems (mealy bug and grafting as a preventive). Illustrated with three attractive large photos showing Huernia hystrix, Ceropegia distincta subsp. haygarthii and Stapelia maculosa - the latter is an odd choice (being a garden hybrid of unknown parentage) considering that there are so many attractive, native South African species to choose from! (24) Morse,D.H. & Schmitt,J. Maternal and paternal effects on follicle production in the milkweed Ascleplas syriaca (Asclepladaceae). Am. J. Bot., 70: 1304-9, 1991. (25) Newton,L.E. A new record for In Raphlonacme. EANHS Bull., 21: 30, 1991. A new Kenyan record for Raphionacme michelii De Wild., known previously from the Kimbala area of Zaire. The other recorded Kenyan species in this genus are R. madiensis, splendens and borenensis. (26) Nicolson,D.H,et al. Flora of Dominica, Part 2: Dicotyledoneae. Smithsonian Contributions to Botany, No.77 , pp.274, 1991. Six species, one from each of the genera Asclepias, Calotropis, , Marsdenia, Mate/ea and Metastelma are recorded for the flora of Dominica. A key is provided, and each species is described briefly. ( 2 7) Pllbeam,J. The Stapelleae In turmoil. The Cactus File, 1: 8-11, 1992. A suivey of what the author considers to be "the present state of play" of name changes for stapeliads since, "the last few years have seen more shuffling of names in the Stapelieae than in any other group of succulent plants". The article, unfortunately, is littered with mistakes. Even the name of our society is given as "Asklepios"! The Stapelieae is considered to comprise thirty genera, each of which is described briefly, but here the author is somewhat out of date. For example, Lavrania contains a single species; here John actually contradicts himself when he says "(2 species): recently created for one species"; what is this meant to tell us?! For at least four other genera he's got the species totals wrong, since recent changes and new descriptions have occurred in Caralluma, Pachycymbium, Rhytidocaulon and . This hardly constitutes a state of the art review of stapeliads, as some of these changes date back to 1989 and 1990. The accompanying 12 photos, two of which are in colour, are good though; just a pity that the quality here isn't matched by that of the text. (28) Pokras,R.S. The medical anthropology of the anti-aging soma and hoama of the Indian Samhltas. Brit. Cact. Succ. J., 9: 92-7, 1991. An unconvincing discussion implicating Sarcostemma as an ancient Indian medicinal plant; confusion with other plants, notably Ephedra, results in unsubstantiated evidence. Most frustrating of all is the use of Indian terminology, much of which is unexplained and undefined. Il lustrated with various irrelevant black and white photos, including one showing cultivated specimens of s. viminale subsp. stocksii. (29) Preston-Mafham,K. Madagascar - A Natural History. Facts on File, Oxford, pp.224, £19.95, 1991. This is a wonderful introduction to the natural history of the fascinating island of Madagascar. Most of the book is taken up with the endemic animals, notably the lemurs, while only twenty pages are given over to the plants, where the succulents feature prominently. The succulent asclepiads form only a small part of the remarkable endemic flora of the island, for which the author records Ceropegia (7 spp.), Cynanchum (20 spp.), Folotsia (5 spp.), Karimbolea (1 sp.), Sarcostemma (3 spp.) and Stapelianthus (a spp.). The photography is superb, but unfortunately for the asclepiads only the somewhat unattractive Folotsia floribundum is illustrated in colour. Overall, the book is highly recommended to anyone interested in general natural history. (30) Rahman,M.A. Polllnarla of some tropical, Asian Asclepladaceae. In P.Baas et al. (eds.) The Plant Diversity of Males/a, Kluwer Academic Publishers, The Netherlands, pp. 83-92, 1990. Po llinaria of 35 tropical Asian asclepiad species from 21 genera (including Ceropegia, Dischidia and Hoya) were studied, and a comparative account of 11 morphological characters was tabulated. The observed variation is shown to be of taxonomic significance and provides diagnostic characters for separating some genera and species within the family. Illustrated with black and white photo,s of pollinaria. (31) Rahman,M.A. & Wllcock,C.C. A taxonomic revision of Calotropls (Asclepladaceae). Nord. J. Bot., 11: 301·8, 1991. The genus Calotropis of the tribe Asclepiadeae (subfamily ) is revised throughout its range in tropical and subtropical Africa and . The three species recognised (C. acia F. Ham., C. gigantea (L.)R.Br. and C. procera (Aiton)R.Br.), are described, keyed out, and illustrated with unfortunately somewhat crude line drawings. Notes on ecology, uses and distribution are appended, and accompanied by maps. The taxonomic position of the genus is discussed and a historical review is provided. For such a widespread and well studied genus, this treatment appears to be somewhat superficial. (32) Rahman,M.A. & Wllcock,C.C. A taxonomic revision of the aslatic genus Pentasacme (Asclepladaceae). Blumea, 36: 109-121, 1991. A complete revision of the Asiatic genus Pentasacme Wall. ex Wight is given with a key to the four species. The distribution, ecology, and comparative morphology of the genus are discusseq and the variation in diagnostic features within the geilus is shown by illustration. Two sections are recognised in the genus. (33) Retlef,E. Stapella lmmelmanlae. Flow. Pl. Afr., 51: t.2003, 1990. Discussion of S. immelmaniae, accompanied by a colour plate showing the habit and floral features, together with a detailed description and a distribution map. This small-flowered species is known only from the Piquetberg Mountain area, where it occurs between rocks in association with three species of succulent euphorbias. (34) Retlef,E. & Hardy,D.S. mamm/1/arls. Flow. Pl. Afr., 51: t.2004, 1990. A lengthy discussion of Q. mammillaris, accompanied by a colour plate showing the habit and floral features, together with a detailed description and a distribution map. This was one of the earliest stapeliads to be recorded, since it was discovered by Simon van der Stel's expedition to Namaquaiand in 1685, It was first published by Burman in 1738, with an illustration copied from a colour painting produced at the time of the Van der Stel expedition. Some 33 years later Linnaeus described the species as Stapelia mammillaris from Burman's drawing. It was renamed Q. mammillaris (L.)Bruyns in 1983. This species has a wide distribution in southern Namibia and western South Africa. (35) Rowley,G.D. 's chandelier Ceropegla - or Is It a myth? /SOCS Newsletter, 4: 5-7, 1991. A short, provocative note, questioning the existence of the type species of Ceropegia, C. candelabrum L., which does not appear to have been in cultivation, at least in European collections. Included is a reprint of an early illustration of the species. (36) Sady,M.B. & Selber,J.N. Chemlcal differences between species of Ascleplas from the lntermountaln region of North America. Phytochemlstry, 30: 3001-3, 1991. Plants of two morphologically similar, but taxonomically contested, Asclepias species were collected from their native habitats. Selected parts of the plants were analysed for cardenolides. The seeds of A. ruthiae contained the cardenolide uzarin, whereas, in contrast, the seeds of A eastwoodiana contained no detectable cardenolides, but the investigation revealed numerous other chemicals not found in A. ruthiae. (37) Samuelsson,G. et al. Inventory of plants used In tradltlonal medicine In Somalla. I. Plants of the families Acanthaceae - Chenopodlaceae. J. Ethnopharmacology, 35: 25-63, 1991. Includes the Asclepiadaceae, but the paper has not seen by this author. (38) Thlede,J. Ceropegla tusca Bolle. Kakt. and. Sukk., 42: centre pull-out No.18, 1991. Brief description of the Canarian species, , together with a discussion of its habitat, relationships and cultivation. Illustrated with photos showing a close up of a flowering stem and a habitat shot. In German. (39) Yamazakl,T. On Cynanchum wilford/1 var. amamlanum Hatuslma. J. Jap. Bot., 66: 60-1, 1991 . The new combination, Cynanchum auriculatum var. amamianum (Hatusima)Yamazaki is published. Text in Japanese and English. (40) Zhao,Z. & Wang,Y. A new species of Marsden/a from Hubel. J. Wuhan Bot. Res., 9: 43-4, 1991. Marsdenia xuanenensis Z.E.Zhao & Y.M.Wang is described and illustrated with line drawings. Text in Latin and Chinese. A note on the Carallumas of Jordan by Colin C. Walker

A chance finding at a recent bookfair sent me delving into my fi les to discover what is known about the stapeliads of Jordan. Whilst browsing at the said fair I came across a title which immediately caught my attention, viz Guy Mountfort's 'Portrait of a Desert' (Mountfort, 1965). Of particular interest to readers of this journal is the fact that the book includes two photos of a flowering Caralluma. The book is the outcome of an expedition to Jordan in 1963 by one of Europes leading ornitholooists, in the company of Sir Julian Huxley - an eminent zoologist, Jan Gillett - a botanist, after whom Euphorbia gillettii Bally & Carter was named, the photographer Eric Hosking, and others. Most of the book deals with Jordan's an imal life, and is well illustrated with good photos, but unfortunately, plants don't featyre prominently. Actually, Jordan isn't noted for it's wealth of succulent plants, so the inclusion of a Caralluma was of immediate interest. Indeed, publicity information on the dust jacket announces that 'the scientific results of their work far exceeded their expectations. Many exciting discoveries were made, such as ... finding a strange, evil smelling species of Caralluma, a plant new to science'. Mountforts description of the discovery of this stapeliad is as follows:

'Eric and John went one day up the gorge to the south of t he Jebel Rum on a botanical photographic session, in the couse of which John made an important discovery. This was a colony of unusual succukents growing amongst the rocks. Jan Gillett pronounced the shrublets to be Stapeliads of the genus Caralluma, but the species was new to him. As his knowledge of desert plants is encyclopaedic and it was the first time we had seen him stumped, we were impressed. The succulents had an upstanding finger-like growth. At the tips of the th ick, knobby branchlets were clusters of foul-smelling, star-shaped magenta flowers, their yellow throats finely dotted with black. These at first appeared to be crawling with small insects, as the clusters were seething with movement. Inspection with a magnifying glass, however, revealed a mass of minute, vibrating hairs, hich the least breath of air kept in motion like the waving tentacles of sea-anenomes. The combination of this curious action and the smell of rotting carrion attracted flies, wh ich thus pollinated the flowers. Specimens were collected and after examination at Kew it transpired that the species may be quite new to science. A small stub broken of one of these interesting if rather repellant plants is flowering in my greenhouse as I write.

The plant is well illustrated in the book, with two habitat shots, one in black and white showing a large clump in flower, whilst a close up in colour shows a few flowering stems.The plant has in fact turned out not to be new to science at all, but is in fact Caralluma tuberculata N .E.Br., (Bruyns, 1986). who says that 'the next mention of it is in Mountfort (1965) where two pictures were published of an 'unknown' Caralluma of which three plants were found in the Wadi Rum by the Mountfort Jordan expedition in 1963. A small piece of this collection was deposited in the spirit collection at Kew (Gillett 16108) under the name C. aaronis (Hart)N.E.Br. but this is also clearly C. tuberculata. 'Additionally Bruyns says of this species that it ' has suffered from being contused with other species right from the beginning'. It has a disjunct distribution, occurring in southern Jordan and south into the western part of the . There is then a large gap eastwards til l north-east Afghanistan and north­ west . The plants from Arabia were described in 1962 as a separate species, Caralluma plicatiloba Lavranos, which is generally what the plant is known as in cultivation. However, th e Arabian and Jordanian material are clearly conspecific with the species further to the east. Bruyns states that ·ovcer th is large range, C. tuberculata shows very little floral variation even down to the distinctive shape of the buds'. The illustration included here (Figure 1) is taken from Ali (1983) and is presumably based in Pakistani material, although the author does not provide the re levant data. Incidentally, the same author states that the plant is eaten raw or as a vegetable, and is reputed to be a cure for rheumatism! So although the Caral/uma from the Mountfort Expedition has turned out to be an extension northwards of an already described species. it is the one and only record for C. tuberculata in Jordan.The story does not, however, end here for this is not the only Jordanian species of Caralluma. Way back in 1885 Hart described another species as Boucerosia aaronis form a single collection (Hart. 1885), and indeed at the time of the now famous monograph of Stapeliads (White & Sloane, 1937), this was the only species recorded for Jordan. Buyns (1986) says that' Caralluma aaronis does not appear to have been recollected and remains known from Hart's original collection and his illustration only ... If his figure [which is reproduced by White & Sloane] Is accurate then it would appear that this species represents an intermediate stage between C. tuberculata and C. europaea (Guss.)N.E.Br.: the leaves are remarkably like those of C. tuberculata (and unlike those of C. europaea) but the flowers have a shallower tube and broader corolla lobes than C. tubercu/ata and are much more like those of C. europaea, though they are said to be minutely puberulous sometimes, which is more likr the former than the latter. Hart records seeing many plants and he found them in flower, but it is not clear how typical the specimen he depicted was of the population he saw. This area requires further investigation.' Later, Bruyns (1987) whilst investigating the Carallumas of Israel, reports that 'in 1984, plants were photographed in flower just north of Petra [Jordan] where Hart originally col lected his material. Acareful examionation of these [Lindner, s.n.,HUJ) shows that the stems and flowers in this picture correspond very closely with the typical C. europaea var. Judaica even as far as the dark tips of the coroll a lobes which have become lost from Harl 's picture, but are typival of al the Israeli forms of C. europaea. Harts species is, therefore, reduced to synonymy.' (Three additional collections of var. Judaica are recorded from around Petra, collected in 1985 (Davis), 1980 (Frey et al.) and 1984 (Lindnel).) This conclusion is fo llowed by Gilbert (1990) in his review of Caralluma.

To summarise, then, only two species of Caralluma are known from Jordan, viz: (1) Caral/uma tuberculata N.E.Br. syn. C. plicatiloba Lavranos (2) Caral/uma europaea var. judaica M. Zoharysyn. syn. C. aaronis (Hart) N.E.Br.

Clearly the stapeliads of Jordan and indeed the succulent flora in general are of limited diversity, but merit further investigation since, as far as I can ascertain, only 5 collections of Caralluma are recorded. Further fieldworl< wi l undoubtedly unearth more interesting records. For example, I wouls speculate that on the basis of th distribution map provided by Bruyns (1987) for C. sinaiaca, which is presently known from surrounding lsrale, Egyptian Sinai and Saudi Arabia, It would seem highly lil

References

Ali , S. I. (1983) Asclepiadaceae in E. Nasir & S.I.Ali (eds.) Flora of Pakistan, No. 150, pp. 1-65, Karachi, Pakistan. Bruyns, P.V. (1986) Miscellaneous notes on Ceropegieae (Asclepiadaceae). Bradleya, 4: 29-38. Bruyns, P.V. (1987) The genus Caralluma R. Brown (Asclepiadaceae) in Israel. Israel J. Bot., 36: 73-86. Gilbert M .G. (1990) A review of Caralluma R.Br and its segregates. Bradleya, 8: 1-32. Hart, H.C. (1885) Report on the Botany of the Sinai and South Palestine. Trans. Roy. Irish Acad.,28: 436,t.17. Mountfort, G. (1965) Portrait of a Desert. Collins Lodon. White, A. & Sloane, BL (1937) The Stapelieae. Ed.2, Vol.1, Pasadena, California. Figure 1. Caralluma tuberculata N.E.Br. A, part of plant with flowers; B, flower; C, corona and gynostegium (face view); D, corona and gynostegium (lateral view); E, fruiting branch. (From Ali, 1983.)

A5Kl.~?l05 19 Asctepias has not had a very large press recently, most of the articles already published appeared some time ago. The fol lowing article Is taken with permission from The Hardy Plant 13 (2) (1991 ), published by the Hardy Plant Society. Sultry an.d Seductive Stran9-,er: . A. Note on Asclep1as ~ynaca and some questions by Tim Longville

Essentially this is a song of praise for one of my new passions this season. What style! What grace! What beauty! Why doesn't everybody grow it? The handsome mid-green oval leaves, up to 8 in. (20cm) long and 3 - 4 in. (7 - 10 cm) broad, on stout stems which need no staking, combine to make a clear and shapely statement up to 3ft. (90 cm) or more in a sunny place. (At least, that is the height indicated in the books but here, in a narrow border at the foot of a sunny wall, it's already 5-6 ft. (1.5- 1.Sm) and rising.) It seems to be reliably hardy though it does have the unnerving habit, In Cumbria at least, of reappearing rather late: well into May this year. Graham Stuart Thomas suggests that some Asclepias species have wandering roots but I've seen no sign of that with A. syriaca (perhaps I should say'not yet' , to be safe). The flowers, a subdued but elegant soft pink are fascinating in form . Though individually small, they're carried in clusters of up to a couple of dozen; each flower begins by looking like a tiny closed jewel-case, the five-petalled top of which then reflexes to reveal five projecting 'honey-horns'. Sweetly honeyed and insidious, the perfume from the flowers will suffuse the air for yards around on a warm evening. The odd thing is that the RHS Gardeners Ency/opedia (which describes it but has no picture) makes no mention of Its perfume ( my plants came from RHS seed and seem to agree with the rest of the RHS Encylopedia description so I assume that what I see is what I expected to get) and Graham Stuart Thomas, who describes several Asclepias species (AA. speciosa, doug/asii, hal/iJ; incarnata and tuberosa, though not A. syriaca), says nothing about the scent of any of them .

Comparing plants to actors, without getting too close to Pseuds' corner, A. syriaca isn't a star; it won 't turn heads at 20 paces. Like the best sort of supporting character actor, if you pay attention to it, it will reward you with unexpected nuances and depths (so it needs to be placed where it can be appreciated by an 'audience'). It will perform reliably and gracefully throughout a five month run and, at the end of July and the beginning of August, it wi ll give you a bonus of two or three weeks flowering flourish. Since th is is the first year it's flowered for me, I've no experience yet of the interesting sounding 'narrowly ovoid fruits', wh ich the RHS Encylopedia attributes to A. syriaca and to several other Asclepias species but, given the intensity of interest shown in the flowering clusters by a huge number of , I soon shall have.

So, the queries: Is A. syriaca indeed scented in the experience of other members? What other Asclepias species do members grow? (Apart from those I've already mentioned, the specialist societies have also offered seed of A. curassavica in recent years and The Plant Finder lists AA. albicans, physocarpa, purpurascens, and viridiflora). What is known of size, style, hardiness (and scent!) of other species currently available? Are there other species, not currently available which might be interesting? Are there, ln short, other Asctepias addicts who could tell us more about this odd but interesting group of plants? Oh, and one last query: Why 'Asclepias' ? A. WOQD A.BOUT NA.MES Tim Longville asks Why Asclepias? A good question as it is also the reflected in the name of this Journal and our Society. Asclepios (male) is the Greek god of healing. Asclepias (neuter) is another form of the same name. It is also found in the literature as Asclepius, though the Romans called him Aesculapius. Asclepius eventually had a whole pantheon of healers associated with him, including his two daughters. Hygieia and Panaceia. Incubation was the practice of sick Greeks and Romans, sleeping within the precints of a temple to Asclepius, for a vision of the healing god, who would reveal a remedy for the sleeper's il lness in a dream. At the time of Claudius, sick slaves would be left in the temple until recovery or death. If the former occurred, the slave would then be a free man - no doubt an inducement to become ill in the first place! In view of the medical uses of a few of its species, Asclepias was chosen as an appropriate name for the genus. In the Americas and Africa, the roots of the plant were used particularly for chest complaints (hence the name 'pleurisy root' for A. tuberosa), but also for curing warts, worms and other conditions. This journal started out in life as 'Asclepiadaceae', which turned out to be a rather cumbersome and confusing title. It was with No. 23 that it became 'Asklepios'. Phil Clark. N.E.BROWN'S REMINISCENCES ON STAPELIEAE by Geoff Hedgecock

In November 1931 'The Cactus Society' was inaugurated in London. At this first meeting, a regu lar programme of meetings and the production of a society journal were amongst the matters approved.

Dr.N.E.Brown was one of the early members and wrote an article for the society's meeting in June 1932 entitled 'About Succulent Plants - What I Learnt at My First Introduction to Them', which was published in the first two issues of Vol 1 of the Cactus Journal.

At this time Brown was the doyen of British botany, having worked for over 40 years at the Kew Herbarium. where his research into the Asclepiadaceae culminated in the publication of monographs on that fam ily in the Flora of Tropical Africa 1904 and the Flora Capensis 1909, besides wh ich he contributed a continuous stream of short publications on the Stapelieae appearing in the Gardeners' Chronicle from 1875 to 1935.

Brown wrote his article to the Cactus Journal at the age of 82, whilst still researching into succulent plants, his major interest in his later years being the succulent Mesembryanthemaceae. He continued to contribute to each issue of the Cactus Journal up to his death in 1932.

Brown. recalling his early interest in Botany, relates that as a schoolboy of sixteen, he was invited by his schoolmaster to see a col lection of ·curious foreign plants'. This was at the gardens of Mr WW Saunders FRS of Reigate, one of the finest collections of exotics in the mid-nineteenth century, being in the charge of Mr Thomas Cooper who had made extensive collections for Saunders in Southern Africa.

Cooper gave the young Brown much information about the plants in the collection, Including how they grew in their native habitat. Many of the plants were originally part of Haworth's fine collection, dispersed at his death in 1833.

Brown goes on to say:

Among the multitude of strange plants I saw in that collection, none took my fancy so much as the Stapelias, some of which were in flower; and next to them, the small Mesembs, now put in the Genus Conophytum, attracted me most. When my visit ended I was given a cutting of Stapelia variegata and invited to come again. That cutting formed the beginning of the fine collection I had many years later when I monographed the whole group.

Brown made several further visits to the Reigate collection before it too was sold and dispersed. The author, however, does not mention in his reminiscences of another attraction at the nursery - he eventually married the daughter of Thomas Cooper!

The remainder of Brown's address to the Cactus Society dealt with his two great loves in the world, namely the Stapelieae and the Mesembs. His account of the Stapelieae is now appended.

I have mentioned that my visit to the collection engendered a great liking for Stapel ias, which greatly increased when I joined the Herbarium staff at Kew in1872, and had access to books and the Kew collection, so I began to study them in earnest preparatory for a monograph. In the early part of my career Sir Henry Barkly was Governor at the Cape, and being himself much interested in the group, sent numerous old and new species of Stapelia and allied genera to Kew. Later, Mr N D Pillans also sent many more, so being desirous of learning what I could about the natural conditions under which these plants grew and their uses, I applied to those gentlemen for information, and the following are extracts of their replies received at various dates between 1875 and 1914. It seems that although widely distributed, yet only one species is found within an area of several square miles, except in Little Namaqualand, which is their headquarters. And in many places where they were once common they are dying out because they are eaten by sheep and goats. They are stated as a rule to grow under the shelter of rocks and low bushy shrubs, where they shade from the noontide heat, with

ASXJ.e.'PIOS 21 good drainage and sufficient soil for their roots to penetrate. I suspect, however, that this shelter is due to the fact that their seeds, which are crowned with a tuft of long hairs, like those of a thistle, are blown about by the wind and are finally stopped by being wafted against a rock or bush and germinate there.

In Namaqualand they mostly occur about 1200-1500 feet above sea level, growing among gneiss rocks, where, in the wettest seasons the annual rainfall does not exceed 5-6 inches.

Possibly some of those present have possessed species of the genus Trichocaulon and therefore know how difficult these plants are to cultivate. This is not surprising when we learn that even under natural conditions they are very selective of their habitat. For Mr Pillans informed me that these plants never grow upon flat country nor upon the eastern side of a hill, but always on the upper western slope of a fair sized hill or range of hills, and then it picks out the driest spot where most shale and least soil is to be found. It is a marvel how they stand the drought. From this it would seem that the right way to cultivate these plants - and also Hoodias - would be to plant them in a pot fi lled with broken rock, which should not be limestone rock, with a little soil among the stones at the lower part of the pot and expose them to bright sunshine.

Plants belonging to the genus Trichocaulon, with spines on them, are called Guaap by the natives and are greedily eaten by Bushmen and Hottentots, wh ich has caused them to become rare. The Dutch also, after cutting their ridges and thorns off, preserve the stems in sugar syrup, and they are said to taste very good. In Bechuanaland the natives slice the stems of Trichocaulon officinalis, dry and pound them to powder, which they boil, and with the water wash their diseased parts three or four times a day as their witch-doctors direct.

Guaap seems to be a generic name for these plants, for Hoodias are called Wolves Guaap, and the hair stemmed Stapelias Slang Guaap, or Snake Guaap, because snakes in Bechuanaland and Griqualand West eat them. Mr Pillans had a Hottentot in his employ, whom he saw take some stems of Stapelia flavirostris, split them down the middle and hold them before the fire to wither and then apply them to a cut, so he made enquiry of the Hottentot as to the uses Bushmen and Hottentots made of these plants, for the Kaffir races do not appear to make use of them, as Stapelias are rare in the region they inhabit. This is what Mr Pillans wrote: Several times I got the Hottentot to taste as many of the edible kinds in my collection as I could spare bits from, and to point out which of the others were edible and which poisonous. He comes from Griqualand West and is well acquainted with most of the species, tor he was with De Wet and then with the British during the Boer War and of his own accord he wandered about Cape Colony and Orange River Colony, so he should have seen many different kinds. As a result, I find that of the genus Stapelia, all in the sections Orbea, , and Podanthes are edible, S variegata and S verrucosa being favourites. Sections Tromotriche and Caruncularia have none that are edible, S pedunculata being known as 'sore head' ('Kop Zeer') , as when a little of the juice gets on your tongue the bitterness gives a headache, and if too much sap is taken violent sickness and death results. In the section Stapeltonia those species with stout hairy stems are poisonous. only a few of the kinds with thin stems are edible. Many Carallumas are eaten, but some are poisonous. Huernias are all edible as far as I can make out although some are not liked, being too bitter. I tried H primulina and could not get the bitterness out of my mouth for two days, but it is eaten by Hottentots as a cure for headache. The stems of certain Duvalias and Piaranthus are taken instead of pills or castor oil.

The sap of Stapelia flavirostris and al lied species of Slang Guaap is used by natives to innoculate themselves to keep off certain diseases. Little slits are made anywhere in the body and the juice rubbed in. They also mix the sap of Slang Guaap with snake poison; the mixture is put on their arrows, so that when a buck is shot, the poison does not circulate through the whole body. He knows decipens and says it has often been his only food for a day when travelling in Griqualand West. Lithops turbiniformis he considered a delicacy. I had often heard of Hottentots subsisting for many days on Stapelieae in the Karoo, for that is about the only food growing wild there. This chap confirmed the fact and tells me that when he left his Boer and walked westward to the towns of the Bechuanas, he was without provisions and his only covering a shirt and sheep's skin, and obtained his food from the veldt, which only provided Guaap (Trichocaulon) and other Stapelias. Water was obtained from wild gourds, and occasio-ally meat was possible when he could kill a bird with a stone. Journeying day after day under such conditions must indeed be unpleasant. It is well known that the flowers of many Stapelieae have a disagreeable odour, and that flies lay their eggs on the centres of the flowers. I never took notice of the species in which flies laid their eggs but in 1902 Mr Pillans wrote to me saying: It may seem strange that although the flowers of Stapelia Pillansii have a very strong scent, yet no flies ever lay eggs on them. This is interesting to me because S Pillansii belongs to the only group that is visited by these blue-bottle flies. I find that all Stapelias having glabrous stems, and flowers coloured like those of S variegata have the same odour, which is like that of carrion. No eggs are laid on flowers of glabrous-stemmed species, no matter how strong the odour. This does not quite correspond with the behaviour of flies in this country, because they sometimes lay eggs on the flowers of S variegata here."

References and further reading

Brown N E(1932, 1937) Journal Cactus Society Vol 1 No 1 (Sept 1932) and No 2 (Dec 1932) Reprinted in JCS Vol 5, No 4 (June 1937) (1904).Asclepiadeae in Oliver & Thistleton-Dyer, Flora of Tropical Africa, Vol 4 Sect 1 pp 231-503 (1909).Asclepiadeae in Harvey & Sonder Flora Capensis Vol 4 Sect 1 pp518 - 1 036 Rowley G D Ed 1989.N E Brown - Stapeliae - Extracted from the Gardeners Chronicle, 1875-1935 International Asclepiad Society reprint CAT AL043UES ~ECEIVE[)

The Editor invites both Nurserymen and Growers to send Catalogues and Lists for mention in this column. Chiltern Seeds, Bortree Stile, Ulverston, Cumbria. LA 12 ?PB Several thousand varieties of seeds are listed in this catalogue, among which are 16 different Asclepiads, just over half of which are non­ succulent. There are 6 sorts of Asc/epias, together with Araujia sericofera, Tweedia caerulea, and Stephanotis floribunda. (Catalogue 50p.) Thompson and Morgan, London Road, Ipswich, Suffolk. IP2 0BASeeds of 7 non-succulent Asclepiads are offered, similar to the above selection, with the addition of gracialis. Sall ey Gardens, Simkins Farm, Adbolton Lane, West Bridgford, Nottingham, NG2 SAS.Plants of 6 species of Asclepias and 2 of Vincetoxicum are available, together with seed of 4 species of Asclepias. Wlaitestone Gardens, The Cactus Houses, Sutton-under-Whitestonecliffe, Thirsk, North Yorkshire, YO7 2PZ Plants fron a dozen succulent Asclepiad genera are offered, usually in variety-around 60 species altogether. For example, 14 Species of Huernia, 16 of Piaranthus, all with collectors numbers, more than one clone of many species being available.

Asclepias syri.aca GROWTH FORMS~:· OF CEROPEGIA

by Phil Clark ... *'This term is used here instead of 'Life Forms' as the emplasis is on how the plants grow. Some authors use the terms interchangeably.

Albers et al. (1991) described the differing strategies found in Ceropgieae that enable the plants to survive in a less than equable climate. The fo llowing comments hav bemn stimulated by that article and by the observation of plants growing in cultivation.

The familiar subsp. woodii is a creeper with heart shaped variegated leaves. This variegation is not caused by lack of chlorophyll, but by the presence of a space between the epidermis and the tissues underneath. Similar variegation can be seen in clones of C. africana and C. rendallli.

A greater range of growth forms is seen in C. africana - both the type and subsp. barklyi. Forms that occur nearer to the coast spread by underground rhizomes, inland forms have stems arising nrom a single caudex. The latter form being better adapted to sharper differences between the seasons. I have observed rhizome development in C. occulta wh ich was obtained as a very small caudex. The first rhizomes arise as side shoots from near to the base of the stems. These grow downwards into the soil, becoming thick underground. No underground shoots arise directly from the caudex. This represents a more fundamental adaptation than the creeping stems of C. I. woodii. In relatively dry and well lit situations, the rhizomatous forms will make make short self-supporting stems - the same plants will develop long climbing stems if well watered - climbing can be an optional extra. This ability to respond to a variation in water supply in this manner is an obvious advantage where water supply is uncertain. These adaptations of C. africana subsp. africana and C. africana subsp. barklyiraise an interesting question - did the growth forms arise separately In each subspecies, or did the different growth forms give rise to the same floral features? The selection pressure for the growth form would have been the environment, that for the flowers the pollinators.

The usual habit of Ceropegia is to grow within a bush or in open grassland. Unfortunately, relatively little is known about the grassland species as their thin stems and leaves are such an effective disguise that they seem to disappear completely into the surrounding vegetation. As the grassland species are so inconspicuous in the wild, seed is virtually impossible to find so they are probably not in cultivation. However, when the flowers do occur, they can be most attractive - the one time that conspicuousness is needed in order to attract pollinators. Many of the familiar kinds that are found in cultivation grow within bushes in the wild. These bushes are very thorny, so· preventing the Ceropegias from being eaten by the local herbivores and humans who find them to be palatable. The bushes also provide shade, humidity and litter - points to be remembered in cultivation. Though Ceropegias, like other Asclepiads, contain latex, this does not seem to deter herbivores. It does seem possible, however, that it reduces predation by insects. It would be interesting to undertake feeding experiments to see it this was the case.

Despite the leafy growth in cultivation, Ceropegias can be difficult to find in habitat. C. steno/oba leaves look similar to those of the much more common Pentarrinhum insipidum, those of C. paricyma are similar to those of a Cucurbit, while the varied leaf shapes of C. meyer/ imitate a variety of plants (Peter Pons, in this issue). C. ampliata, and others with similar vegetative form seem to fade into the background of the bush up which they are growing.

Some species have a growth form which appears to be particularly suited to their habitat. An obvious example is C. stapeliformis, the creeping stems grow amongst and half hidden by, the leaf litter. Bruyns (1980) describes how the grey wrinkled creeping stems of C. stapeliformis subsp. serpentlna can be mistaken for dead fallen twigs, and how the mottled stems of C. s. stapeliformis blend in with the shadows inside a bush. (Bruyns 1985). Cultivated clones of C. stapeliformis8vary from dark and mottled to silvery, which probably reflects the variation to be found in the wild. It would be most interesting to investigate the relationship between the background colour of the leaf litter and stem colour. From these thick creeping stems, thinner climbing shoots develop which clamber through the bush to expose the flowers to the outside for pollination. C. cimiciodora is similar, but the stems are even thicker - it comes from more arid areas than C. stapeliformis.

Other species also have the same habit of producing creeping and then climbing stems, but this may not be so obvious in cultivation as growers often twine the long shoots around sticks, so obscuring their natural habit. This habit of forming vegetative and then flowering shoots enables the plant to colonise the space under a bush effectively before the flowering stems are sernt up. C. albisepta var. bruceana (syn. C. succulenta) is a further example. It comes from dry forest regions, so it dislikes sun and excessive damp at the root. Left to its own devices, this will form long horizontal vegetative stems which can be somewhat inconvenient in the average greenhouse! These are happiest under the staging in the shade - if tied up in the light, they may well stop growing. Climbing stems will eventually form, which are much thinner than those of the vegetative growth, but even these prefer shade. The posession of dark green leathery leaves indicates that this a plant of deep shade. The strategy of such shade plants is one of survival - a low metabolic rate that reduces the need for rapid photosynthesis. They are unable to make use of high light intensities (Grime 1979).8 Lack of attention to its requirements and its growth habit probably accounts for its poor reputation for flowering. The attractive flowers are worth the trouble as they are relatively large, spotted red on a white background with a greenish t ip. Some forms of C. sandersonii appear to have a similar vegetative phase, others do not. One plant of mine on a high shelf was pendulous for 1 .5m, then turned to grow upwards, the first flowers appearing once the stem had climbed 1.35m, after which numerous flowers were produced. Other clones do not seem to have this vegetative phase - young plants climb straight away. This species is more tolerant of differences in light intensity than C. albisepta var. bruceana.

As Albers et al. (1991) pointed out, Ceropegias are less well able to adapt to arid climates than Stapelieae. However, many do have to survive a dry season. Some, eg. C. I. woodii and C. africana, often keep their top growth even though they may have a caudex or rhizomes to see them through the dry season. Others are normally completely . C. pachystelma, though closely related to the above, loses all of its top growth in the autumn - it just disintegrates! Towards the end of the season, sections of the stem just fall out so there may be no connection between shoot and root! C. nilotica and C. crassifolia are also deciduous. These species die down to a cluster of fusiform roots. These fleshy roots taper at each end (hence 'fusiform'). They can be a little tricky to l

The species ('stick Ceropegias'), eg. C. dichotoma, are distinct as they form thick succulent non-climbing stems - which can be as much as 4cm thick. Living on old lava flows, and other well drained habitats in the open, they do appear to have some resistance to dessiccation. Lems and Holzapfel (1983) came to the conclusion that their ability to withstand dessiccation was due to greatly reduced surface area in relation to the volume of the stems, and the reduced number of stomata. However, they point out that the Canary Islands are humid, the humidity being not less than 50% RH. When repotting plants in the spring (April), when the tops appeared to be quite dormant, it was obvious that the roots were still active. One can speculate that this root activity enables the plants to exploit deeper sources of water during the dry season.

Though Ceropegias are usually grown for their fascinating flowers, there is also much interest in the observation of the ways in which the plants grow. It is hoped that these notes will encourage growers to tal

Albers, F., Delfs, W., Kusch, W., Meve, U. (1991) Life forms of the Ceropegieae and Stapelieae (Asclepiadaceae) in arid areas of Africa. Asklepios 54 p.43-51 Bruyns, P.V. (1980) Ceropegias of the Pretoria area. Asclepiadaceae 21 p.2-20 (1984) Ceropegia, Brachystelma and Tenaris in South West Africa. Dinteria 17 p.3-80 (1985a) Notes on Ceropegias of the Cape Province. Bradleya 3 p.1- 4 7 (1985b) The genus Ceropegia on the Canary Islands (Asclepiadaceae Ceropegieae). A morphological and taxonomic account. Beitr. Biol Pflanzen 60 p.427~ 458

Dyer, R.A. (1980) Asclepiadaceae (Brachstelma, Ceropegia, Riocreuxia) in Leistner O.A. (Ed.) Flora of Southern Africa 27 (4)

Grime, J.P. (1979) Plant strategies and the vegetation process. John Wiley & Sons

Huber, H. (1957) Revision der Gattung Ceropegia Mem. Soc. Brot. 12 p.1-203

Lems, K. & Holzapfel, M. (1983) - an unusual stem succulent from the Canary Islands. Asklepios 27 p.45-48