A new intergeneric hybrid genus xGastonialoe is named for crosses with the parentage Gasteria x Gonialoe (Aloe). An attractive cultivar in this new nothogenus is named xGastonialoe 'Gordon Rowley', in honour of an ardent champion of such hybrids

Walker, Colin C.

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Open Research OnlineThe Open University’s repository of research publicationsand other research outputsA new intergeneric hybrid: xGastonialoe ’GordonRowley’Journal ItemHow to cite:Walker, Colin C. (2017). A new intergeneric hybrid: xGastonialoe ’Gordon Rowley’. CactusWorld, 35(1) pp.21–22.For guidance on citations see FAQs.c© 2017 BCSS, authors and illustrators of individual articlesVersion: Version of RecordCopyright and Moral Rights for the articles on this site are retained by the individual authors and/or other copyrightowners. For more information on Open Research Online’s data policy on reuse of materials please consult the policiespage.oro.open.ac.uk×GastonialoeThe genus Aloe has recently been split based on newmolecular evidence.  This has resulted in the excisionof a small number of species into segregate genera.Grace et al (2013) first separated the tree aloes intoAloidendron and Kumara and the scrambling speciesof Aloe into Aloiampelos.  This was followed byManning et al (2014) who separated off a smallnumber of southern African species into Aristaloe andGonialoe.  Nevertheless, this has left Aloe largely intactwith around 500 species, including about 60 subspeciesand varieties (Carter et al, 2011). These changes weresummarised in this Journal for those wishing to followthe latest developments (Walker, 2013, 2014).Aloe and its close relatives are very easily hybridised,with a large number of hybrids already known.  Ofparticular interest here is the new genus Gonialoewhich includes just three species, all formerly includedin Aloe: Gonialoe dinteri, G. sladeniana andG. variegata (Manning et al, 2014).  The latter species,known most familiarly as Aloe variegata, is one of theparents of several hybrids.  When hybridisationinvolves a second genus, an intergeneric nothogenus isrequired.  Here we are concerned with crossesinvolving G. variegata and the genus Gasteria.Intergeneric hybrids with the parentage Gasteria ×Gonialoe require a new name, for which the followingis proposed:×Gastonialoe C.C.Walker nothogenus nov. (Gasteria× Gonialoe)×Gastonialoe ‘Gordon Rowley’ cv. nov.It gives me great pleasure to name a clone of anintergeneric hybrid after Gordon Rowley, past BCSSPresident and editor of Bradleya, who has long been achampion of such hybridisation and has himselfnamed many intergeneric hybrids.  Rowley (1982)catalogued intergeneric hybrids in succulents, and thelist has been added to on several occasions since, forexample, Rowley (2013b, 2014a,b).  The current stateof play on hybrid succulents in general andintergeneric hybrids in particular, is well summarisedin Gordon’s latest book (Rowley, 2017).The clone I am naming in Gordon’s honour (Fig. 1)has been in cultivation for many years and I havegrown it since 1989 as Gasteria batesiana × Aloevariegata.  However, with the generic concept I amadopting here, the parentage becomes Gasteriabatesiana × Gonioaloe variegata. This is a very attractive, robust and hence desirablecultivar that deserves its own cultivar name.  I believethat this clone has been illustrated at least twice(Newton, 1998: 117; Rowley, 2014b: 23) but as far as Ican ascertain, this particular clone has never received aname until now.×Gastonialoe ‘Gordon Rowley’ is clearly intermediatebetween its two parents (Fig. 2).  The plant formsrosettes up to about 15cm across, branches freely fromthe base, thus is readily propagated from stem cuttings.The leaves are deltoid and shallowly V-shaped in crosssection, with a prominent channel, hence being moresimilar in shape to those of the Gonialoe parent, butunlike G. variegata, the leaf arrangement is rosulateand not 3-ranked.  The surface texturing, in contrast, ismore closely related to that of the Gasteria parent,A new intergeneric hybrid:×Gastonialoe ‘Gordon Rowley’Colin C WalkerA new intergeneric hybrid genus ×Gastonialoe is named for crosses with the parentage Gasteria× Gonialoe (Aloe).  An attractive cultivar in this new nothogenus is named ×Gastonialoe ‘GordonRowley’, in honour of an ardent champion of such hybrids.  Photography by the author.Fig. 1  ×Gastonialoe ‘Gordon Rowley’ in a 15cm-diameter panbeing heavily marked with prominently raised whitishtubercles, whilst the characteristic banding orvariegated pattern of G. variegata is absent.  The leafmargins, though, are similar to G. variegata, beingwhite, cartilaginous and armed with minute teeth.Interestingly, in the 27 years that I have grown thisplant I do not recall it ever having flowered.Older ×Gastonialoe cultivarsOther, older cultivars involving intergeneric hybridswith a species of Gonialoe have been recorded byNewton (1998, 2001) and Rowley (2014b).  All of theseinvolve G. variegata as one of the parents together witha range of Gasteria species.  The other species ofGonialoe, G. dinteri and G. sladeniana, are much rarerand more temperamental in cultivation and hence, asfar as I can ascertain, have not been used in theproduction of intergeneric hybrids.I list here six additional ×Gastonialoe cultivarsinvolving G. variegata (see Rowley (2014b) andNewton (2001) for further details); it is currentlyunknown if any of these are still in cultivation, sincesome originated over 100 years ago:(1) ×Gastonialoe ‘Mortolensis’ (= Aloe ×mortolensisBerger = ×Gasteraloe mortolensis= Gonialoe variegata× Gasteria acinaciformis).(2) ×Gastonialoe ‘Pfrimmeri’ (= ×Gasteraloe pfrimmeriGuillaumin = Gonialoe variegata × Gasteria sp).(3) ×Gastonialoe ‘Radlii’ (= ×Gasteraloe radliiL.E.Newton = Gonialoe variegata (or Aloe serrulata) ×Gasteria sp.).(4) ×Gastonialoe ‘Rebutii’ (= Aloe ×rebutii hort. exBerger = ×Gasteraloe rebutii = Gonialoe variegata ×Gasteria sp.).(5) ×Gastonialoe ‘Sculptilis’ (= ×Gasteraloe sculptilisG.D.Rowley ex L.E.Newton = Gonialoe variegata ×Gasteria ×cheilophylla).(6) ×Gastonialoe ‘Smaragdina’ (= Aloe ×smaragdinahort. ex Berger = ×Gasteraloe smaragdina = Gonialoevariegata × Gasteria ? candicans).Other ×Gastonialoe cultivars involving G. variegata asone of the parents and a wider range of Gasteriaparents were listed by Newton (1998), but none ofthese were provided with cultivar names.ACKNOWLEDGEMENTS:I thank Gordon Rowley for the inspiration to name this new cultivarin his honour.  Thanks also go to Al Laius for his advice and to mywife Marjorie for comments on an earlier draft of this article.LITERATURE:Carter, S, Lavranos, J J, Newton, L E & Walker, C C (2011) Aloes. Thedefinitive guide.  Kew Publishing, Royal Botanic Gardens, Kew /British Cactus & Succulent Society.Grace, O M, Klopper, R R, Smith, G F, Crouch, N R, Figueiredo, E, Rønsted, N & van Wyk, A E (2013) A revised generic classifi-cation for Aloe (Xanthorrhoeaceae subfam. Asphodeloideae).Phytotaxa 76: 7−14.Manning, J, Boatwright, J S, Daru, B H, Maurin, O & van der Bank,M (2014) A molecular phylogeny and generic classification ofAsphodelaceae subfamily Alooideae: A final resolution of theprickly issue of polyphyly in the Alooids?  Syst. Bot. 39: 55−74.Newton, L E (1998) Unnamed hybrids of ×Gasteraloe alliance.Bradleya 16: 115–118.- (2001) ×Gasteraloe in Eggli, U. (ed.) Illustrated Handbook ofSucculent Plants. Monocotyledons. Springer-Verlag, Berlin, etc.,pp.190–192.Rowley, G D (1982) Intergeneric hybrids in succulents.  Nat. Cact.Succ. J. 37: 2–6, 45–49, 76–80, 119.- (2013a) Generic concepts in the Alooideae Part 3 – The phylo-genetic story.  Alsterworthia International 13(2): 24−26.[Republished with amendments as Alsterworthia InternationalSpecial Issue No.10: 3−6.].- (2013b) Tulista (Aloe) aristata e i suoi ibridi/and its hybrids.Cactus & Co.17(2/3): 102–113.- (2014a) Intercladal hybrids. CactusWorld 32(1): 25−26.- (2014b) Intergeneric hybrids in the Asphodelaceae subfamilyAlooideae – 2014 update.  Alsterworthia International 14(2):16−28.- (2017, in press) Succulents in cultivation – breeding new culti-vars.  British Cactus & Succulent Society, Hornchurch, Essex.Walker, C C (2013) All change in Aloe and Haworthia.  CactusWorld31(4): 297.- (2014) More change in Aloe, Haworthia and their close relatives.CactusWorld 32(2): 138−139.Dr Colin C Walker, School of Environment, Earth &Ecosystem Sciences, The Open University, Milton Keynes,MK7 6AA, UK.Email: c.walker702@btinternet.comLayout by Alice Vanden BonFig. 2  ×Gastonialoe ‘Gordon Rowley’ (front) with its parentsGonialoe (Aloe) variegata (left) and Gasteria batesiana (rearright), showing clearly the intermediate features of thisintergeneric hybrid

A new intergeneric hybrid: x<i>Gastonialoe</i> 'Gordon Rowley'

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