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BCSS Southampton & District Branch – May 2005 Newsletter Page 2Thanks are due to David Corina for providing thefollowing write-up of last month’s talk by StirlingBaker.Interesting HaworthiasThis was a two-part programme featuring plantsin the first half and slides in the second. Stirlingopened his talk by quoting a definition of(Haworthia) species by Bruce Beyer [fromHaworthiad, the journal of the Haworthia society]which he, and most of the audience, foundincomprehensible! Bayer is probably the currentauthority on the genus, and his system ofnomenclature is generally accepted.There is considerable variation in Haworthias,plants of the same nominal species vary widelyover their range and this has led to a proliferationof names. [See postscript 1] Stirling had broughtalong ‘typical’ examples of plants that were‘accepted for the name’ as he put it. Not allHaworthia species were covered, only those thathe thought were worth growing. The plants werediscussed in ‘groups’ based on growth formsrather than the botanical divisions. As most ofthis text is discussing one genus, I shall imitateStirling and omit the ‘H.’ and just give the speciesnames in the account below.Probably most people in the audience had hopedfor lots of tips on how to grow Haworthias, butStirling did not spend much time on this topic.His basic tips were to grow in bright light (to getgood colours) but not full sun all day, and give asmuch air as possible – alpine house treatment!Most Haworthias tend to grow early in the year.Best to repot into one’s own compost, in a deeperpot where possible. This enables you to check theroots and remove any dead ones. Current wisdomstates that Haworthias ‘re-root’ every year. Therehas been much written about composts forHaworthias, and in the past a heavy soil-basedmix was advocated, but current ideas favour alighter mixture containing (expanded) pumice fordrainage, and even growing in the completelyartificial medium Seramis [see BCSS Journal19(3) 2001 p.158]. Suggested mode ofpropagation from seed was to sow about 10 seedson the top of seed compost in a 2" square pot,cover with a sprinkle of silver sand, water fromthe bottom with hot water and enclose the pot in apolythene bag. Keep the seedlings growing on inthe shade.Cuttings are not theoretically possible for thestemless species but it is possible to cut thecentres out of the plants and hope that newrosettes are formed from the stump. Plants cannotbe grafted. Many species will propagate fromleaves, and the stemmed species can have the topsre-rooted (hormone rooting powder and bottomheat recommended). Otherwise plants can besplit up into the offsets and started again – often agood idea for old plants.If you are a real enthusiast (or a masochist!), thenread on … …otherwise go to end!First plants out of the box were the group withsomewhat incurving, soft tufted leaves edged with‘bristles’, typified by arachnoidea, a variable,slow species; a good form of this is scabrispina.Although the leaves are soft, this group of plantscan withstand drought (by closing up the rosette)and strong light (the bristles filter the sun). Allare slow growers, usually solitary for theirlifespans with us! Other familiar species in thegroup are bolusii and its var. aranea, and var.palmiana(?) which looks like arachnoidea; thennortieri, difficult, keep cooler and out of the sun;and semiviva, an autumn grower. Next camemucronata and its var. morrisiae and the similarhabdomadis var. inconfluens. Lastly, the reallychoice species: lockwoodii needs no introductionbut Stirling reserved the term ‘gems’ for the smallsoft leaved species pulchella (the original form,very slow, 15 to 20 year old plant still in a 23/4in. pot), pubesens, archeri (now in withmarumiana) and archeri var. dimorpha.Although larger and easier to grow, cooperi andform venusta were included in this group. Withall of the above, there are many clones around andit is best to choose a good one. A general hint oncultivation was that if the rosette is tightly closed,give a drink, if open, do not!Probably the most popular group are the flatleavedretusae types, typically the emelyae-pictacomplex. There are lots of forms and varieties,e.g. emelyae var. major. Need to buy these “onsight” to get good forms. A clumping species ispygmaea and pygmaea var. argentea maculosa(but some are wrongly named, ‘splendens’ nowregarded as magnifica splendens); choose goodleaf markings. H. comptoniana is now regarded asa variety of emelyae and can grow quite large; itappreciates some shade. For mirabilis, the var.badia is the best, and var. buekmannii clumpswell but then falls to bits, so start again!Bayeri/uniondalensis is liable to burn if kept toosunny. Other popular species in this group aremaughnii (which can get quite big) and truncata,which really need no introduction, but others are
BCSS Southampton & District Branch – May 2005 Newsletter Page 3less common such as pygmaea (var. ‘Frosty Top’is nice) and springbokvlakensis (remaining small)and bruynsii. (The latter is still rare in collections– perhaps due to its high price, difficulty ofpropagation and slow growth; most plants offeredrecently are most likely to have beenmicropropagated.) Last in the group is tesselata, agood grower – there are some good small clonesand the cv. ‘Lady Gray’ is recommended.On to the ‘hard’ leaved ones. coarctata (esp. asmall form var. bellula) and reinwardtii arecommon, but some forms are difficult. Someplants of this group develop ‘stems’ which aresometimes spoilt by leaves part way up dyingback. Stirling said that the cause of this isunknown. Many of this group develop prettytubercles, often white and pearlescent, giving riseto good markings. One of the potentially tallestspecies is pumila, but minima belies its name andis certainly nowhere near being the smallestHaworthia. For minima, the var. ‘Bryan Makin’is a fine form. Slow and more choice are sordidaand its var. lavrani (possibly the same as sordidavar. agavoides) and scabra, but scabra var.morrisiae is easier.Haworthia is a genus that lends itself tohybridisation, but Stirling warned against any oldhybrid – they must have some merit to be retainedas many are not worth growing. Joyce Coccoza isamong those who produce many attractivehybrids, in addition to her excellent drawings ofHaworthias. The Japanese also produce manyfancy varieties. Many such crosses were shown:for example maughnii x badia (a good showplant), arachnoidea x truncata, (severalvariations) and herbacea x emelyae, perhaps thebest known of Joyce’s crosses.At the start of the second half, which was a slideprogramme, Stirling showed variegated forms ofmany of the species discussed earlier. [magnifica,venosa (unstable), limifolia (stable), cymbiformis,retusa, viscosa and maughnii. Here Stirlingsneaked in Gasteraloe x ‘Green Ice’, a veryattractive plant with possibly a variegatedGasteria batesiana somewhere in its lineage. Thefeeling here is that one either likes them or hatesthem! Some further hybrids were shown here,repeating some we had seen as plants in the firsthalf, plus pygmaea x paradoxa (often differentnames, same cross), comptoniana xspringbokvlakensis (reasonably quick growing),limifolia x striata (not easy) and correcta xspringbokvlakensis.Returning to ‘pure’ plants we heard that badia,with thick leaves, is difficult to get to ‘sit’ on thecompost, a miniature form of coarctata, one ofthe smallest rosettes with parksiana (slow, can bedifficult), pubescens (nice), habdomadis var.inconfluens keeps a tight rosette, maraisii (nowunder magnifica) and the lockwoodii trio referredto in the first half, and schuldtiana. Nice veiningis possible on correcta (although this tends to loseleaves and often pulls itself down into the soil).At this point Stirling gave the Haworthias a restwhen he showed a few slides of some othersucculents, the most exciting of which wasMuiria, followed by some Anacampseros andAvonia, Ariocarpus, Brachystelma, a Lithops anda lovely Crassula mesembryanthemopsis.Back to the evening’s main topic. We moved onto splendens x badia crosses, small plants, severalclones, will colour up well in good light but keepthe roots cool. Next, koelmaniorum and some ofits hybrids, pulchella var. globifera(?), semiviva(small and variable), mcmurtryi (some consider avar. of koelmaniorum), tesselata (various patterns,some good, some named) and others seen earlieras plants.Postscript 1. Hobbyists new to Haworthias neednot fret too much about identifying their plants.Although the taxonomy of Haworthia is thesubject of often acrimonious debate, it is mainlythe retusae types which cause problems; probablya good 60% of the species are fairly readilyidentifiable in the newer books, e.g. Bayer’s‘Haworthia Revisited’.Postscript 2. I apologise for breaking my ownrule that the scribe should not write a blow-byblowaccount of a talk. Perhaps that’s because Iam a Haworthia enthusiast! You have the optionto skip the ‘heavy’ bits. And I leave the flowerson my plants, although this is more throughlaziness than intention (unless I’m trying forseed).David Corina
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