Soulll AfncfJn JO(lfllai Of Bo/any 200 1 67 16 1- 168 Copy"gilf@ NiSCPlyLid Prmfcd in SOllth Afflr.a - All fights reserv(1{j souTHAi'ilrcAN JOURNAL or BOTANY ISSN 02~6299 Reconsideration of the status of Lavrania, LarryJeachia and Notechidnopsis (Asclepiadoideae-Ceropegieae) U Meve' and S Liede Department of Plant Systematics, University of Bayreuth, 0-95440 Bayreuth, Germany • Corresponding author, e-mail: [email protected] Received 11 January 2000, accepted in revised form 11 May 2000 Based on morphological, karyological and DNA intermediate position of Notechidnopsis between the sequence data the circumscription of Lavrania Plowes, more distantly related Larryleachia and Lavrania. Larryleachia Plowes and Notechidnopsis Lavranos and Keeping the three genera distinct is the best reflection Bleck is reconsidered. The data presented point to an of the complex relationships within this group. Introduction In Ihe over 30 genera of stem-succulent stapeliads (1992b) repeated it by publishing Leachiella Plowes as sub­ (Ceropegieae) presently recognised (Albers and Meve, in stitute name fo r Leachia Plowes. Again, th is generic name is press a), the generic treatment of the highly succulent illegitimate, since Leachiella Kugrens is an older name for a 'smooth-stemmed ' Trichocaulon species was often subject red alga. Th iS unhappy situation was resolved by Bruyns to controversial systematic co nsiderations (Plowes 1996, (1993) with th e transfer of the smooth-stemmed Bruyns 1993, 1999a). Trichocaulon taxa to th e hitherto monotypic Lavrania NE Brown (1878) Introduced the genus Trichocaulon NE Plowes. However, to reflect the phylogenetic distance of the Br. to accommodate two small-flowered (spiny) species of two speCies gro ups, Bruyns (1993) created two different Hoodia Sweet ex Decne. He subsequently added some sections , Lavrania sect. Lavrania , for L. haagnerae, and more species, including smooth-stemmed re presentatives sect. Cactoidea (AC White and B Sloane) Bruyns for the (Brown 1909). Nel (1933) added the third element under dis­ smooth-stemmed former Trichocaulon species. However, cussion here, Trichocaulon co/umnare Ne t. This concept Trichocau/on sect. Cactoidea is a 'nomen nudum ', so that was adopted by AC White and B Sloane (1937) . Later, this name is not valid either. In 1996, Plowes made a third Trichocaulon columnare, together with Caralluma tessellata attempt by proposing the genus name Larry/eachia PI owes Pillans, were transferred to the new genus Notechidnopsis for Lavrania sect. Cactoidea (illeg. Leachia and illeg. by Lavranos and Bleck (1985) to separate these two rhi ­ Leachiella). But even with this now validly published gener­ zomataceous species lacking the smooth stems of ic name, taxonomic stability in th is group was still not Trichocau/on sect Cactoidea White and Sloane as well as achieved. The transfer of Lavrania (incl. Larry/eachia ) to the spines of Hoodia. In 1986, Plowes described Lavrania Hoodia by Halda (1998) caused temporary regression. haagnerae Plowes, the fourth ceroid multi-ribbed taxon Unfortunately Halda neither co nsidered Nolechidnopsis nor known in the southwestern corner of southern Africa offered any new arguments why these species should be PIowes (1992a), in a fi rst attempt to split the undisputedly added to Hoodia; which in its present circumscri ption is a heterogeneous Trichoca ulon sensu NE Brown and White well -defined and independent genus. and Sloane, transferred all Trichocaulon taxa with spines to Bruyns (1 999a ) probably was not aware of Halda's Hoodia. This generic transfer has been adopted by Bruyns nomenclaturally co rrect transfers when he again 'clarified' (1993), although the number of accepted species differs th e status of Larry/eachia transferring Larry/eachia to considerably between the two treatments. The remaining Lavrania and placing al l species of Larry/eachia , incl uding its smooth-stemmed Trichocau/on taxa needed a new name, type Stapelia cacliformis Hook., in his newly described sec­ because the type species of Trichocau/on, the spiny T pi/­ tion La vrania sect. Cactoidea Bruyns. The new section, iferum L. .f., had also been transferred to Hoodia. Plowes again, is based on the type S. cactiformis. (1992a), therefore, accommodated them in th e new genus The focus of th is study is on the comple x relationships Leachia Plowes . However, this name is illegitimate because between Lavra nia , Larryleachia sensu Plowes and to the it is a later homonym of Leachia Cassini (Asteraceae). In th e sympatric, cereoid and non -sp iny, bltypic Notech;dnopsis. process of correcting his nomenclatural mistake, PIowes Plowes (1986) discussed Notechidnopsis as putative closest 162 Meve and Llede relative of Lavrania s.slr., while Bruyns (1999b) regards Sequences were obtained on an ABI Prism Model 310 Nolechidnopsis as a monophyletic genus most closely relat­ Version 3.0 sequencer. All sequences have been deposited ed to Pectinaria Haw. The following options are examined: at EMBL Nucleotide Sequence Database (Accession • Should Noleehidnopsis, Lavrania s.slr. and Larry/eaehia Numbers AJ4021 16- AJ402162). be regarded as separate genera as proposed by Plowes (1996)? Data analysis · Should Lavrania S.str. and Larryleachia (Lavrania sect. Caeloidea, respectively) be united to Lavrania s.l. while Sequences were pre-aligned wi th Perkin Elmer Sequence Nolechidnopsis IS kept separate (sensu Bruyns 1993, Navigator Version 1.0.1; the alignment was cleaned manu­ 1999a)? ally. The 'Taberlet' alignment (available from the authors) • Should Notec/1idnopsis be united with Lavrania andlor co mprises 12 taxa and 1711 characters [814 sequence char­ Larry/eachia? acters in the ImT-ImL intron (primers a-b), 512 sequence cha racters between the two trn L-exons (primers c-d), and Materials and Methods 384 sequence characters and 1 indel in the ImL-lmF intron (primers e-f)]; 26 data cells are unknown. The ITS alignment Materials comprises 11 taxa and 655 data cells. Both alignments are either available from the authors or can be viewed on the The material used in this study, including voucher speci­ World Wide Web (h ttp://www.uni-bayreuth.deldepart­ mens, is summarised in Table 1. mentslplanta21) . Phylogenetic analysis and tests for clade support were Chromosome counts performed using PAUP version 4.0d65 (PPC) , Swofford (1998) on a Macintosh Powerbook G3. For parsimony Chromosome numbers were established from adve ntitious analysis, gaps were coded as 'missing' and excluded by root tip squash preparations. The root tips were pretreated deletion of 'missing/ambiguou s' and 'uninformative', In a in 0.002M hydroxyquinoline for 4hrs at 20· C (Tjio and Levan second analysis, indels 3bp and longer were coded sepa­ 1950), fixed in Carnoy's solution for 24hrs at 20°C and rately as 'presentlabsent'. Bootstrap search (1000 rep licates) stained with carmine for 24hrs at 60·C (Snow 1963). was conducted under the 'fu ll heuristic' search option , starting trees were obtained by 'stepwise addition' and 'random' addi­ DNA extraction and peR tion sequence with 10 replicates; swapping algorithm was set to 'TBR' and 'MuITrees'. Jackknife resampling (1 000 repli­ DNA was isolated from fres h stem tip tissue according to cates) was set to 50% deletion, and 'Jac' resampling ; the othe r Doyle and Doyle (1987). PCR primers and protocol for the settings were identical to the bootstrap settings. plastid IrnT-IrnL and IrnL-IrnF spacers correspond to Distances were computed using the Neighbor-joining Taberlet el a/. (1 991). algorithm. Al l sequence cha racters were analysed usi ng the The entire Internal Transcribed Spacer region (I TS ) of three options under 'DNA-RNA distances': 'uncorrected (pr, ribosomal DNA was am pl ified using the flanking pri mers 'Jukes-Cantor' and 'Kimura-2-parameter'. ITS4 and ITS5 following a slightly modified protocol from As the results of analyses of the ITS and the 'Taberlet' Baldwin (1992). Th e 25~ 1 reactions contained (in the order of dataset were largely con tradictory, a partition homogeneity addition) : 15 . 8 ~1 sterile water, 2~1 MgCI, (2 5mM) , 1.5 ~1 test (as included in PAUP version 4.0b3a) was conducted dNTP3 (20mM), 25~ 1 10x buffer, 1~IITS4 ( 1~M) , 1~ II TS 5 showing that the datasets are highly significantly discordant (1 ~M ) , 0 . 2~ 1 Taq DNA po lymerase (1 Unit, Oiagen), 1 ~ I tem­ (P = 0.01). Assigning triple weight to the 'Taberle!' data to com­ plate DNA PCR was conducted with an initial 3' at 94°C pre­ pensate for the lesser number of parsimony informative char­ liminary denaturing, and 30 reaction cycles (1 ' at 94°C, l ' at acters of this dataset lifts reduces the discordance (P = 0.06 ); 5rC, 3' at 72°C). still, a com binati on of the data sets does not seem advisable. Table 1: Voucher and locality information for plant material used in this study Species Ori gin Voucher Caral/uma edulis (Edg .) Benth Oman: Ohofar Butler C31 2 UBT Ceropegia nilotica Kotschy Kenya : Mbolo Hill Masinde 836 MS UN Gymnema sylvestre (Retz.) Schult. (Marsde nieae) Cameroon : E Mokola Meve 919 B, UBT Lavrania haagnerae Plowes Namibia : Khowarib Gorge Haagner sub Plowes 5046 PRE, MSUN Larryleachia cactiformis (Hook.) Plowes South Africa : Numees Teissier 097 UBT Larryleachia periata (Ointer) Plowes Soulh Africa : Richtersveld Jurgens s.n UBT Notechidnopsis colum nans (Nel) Lavranos and Bleck South Afri ca : Hell skloof Albers and Meve 30 MS UN Notech;dnopsis tessellata (Pill ans) Lavranos and Sieck South Africa : Nieuwoudtville Meve 256 MS UN Pectinaria articulata (Ait.) Haw. ssp. borealis Sruyns South Afri ca : Heli skloaf Albers and Meve 32 UBT Piaranthus barrydaJensis Meve South Africa : Muiskraal Meve et al. 128 K, MS UN Piaranthus camptus NE Sr. South Africa : Klaarstroom Albers su b K 1123 MS UN Stapefia glandulif/ara Masson South Africa : S Klawer Albers and Meve 04 MSUN South African Journal of BOl any 2001. 67 161-168 163 Results Albers and Meve 45 [MSUN]; figure 3A) and 0 .