BLUMEA 22 (1975) 311—407 Vegetative anatomy and the affinities of Aquifoliaceae, Sphenostemon, Phelline, and Oncotheca P. Baas Rijksherbarium, Leiden, Netherlands Contents Summary 312 Introduction Aims of this study 3 12 Historical 31 2 Synopsis of morphological characters 3*5 > Techniques and materials 3 I( Descriptive part Leaf J anatomy 3 7 2 Nodal anatomy 3 5 2 Twig anatomy 3 7 2 Bark anatomy 3 9 Wood 1 anatomy 33 Discussion of some anatomical characters Indumentum 334 The unspecialized cells of the leaf epidermis 334 The stomatal complex 335 Cork warts 335 Leaf hypodermis 335 Crystals, sclereids, and marginalsclerenchyma 33d Nodal and vascularization anatomy petiole 337 Twig and bark anatomy 33" Wood 338 anatomy Affinities and taxonomic rank Introduction 339 Sphenostemon 339 Phelline 34 2 Oncotheca 355 Nemopanthus 355 and the Celastrales. The position of Icacinaceae, Aquifoliaceae, Phellinaceae, Sphenostemonaceaein 356 General considerations and conclusions 35b The leaf anatomical in Ilex Special part: range Introduction 357 Loesener's for Ilex 357 system Specific descriptions and taxonomic notes 359 anatomical Lists ofDex species with certain leaf characters 387 Comparison of leaf anatomical data with Loesener's system 390 Subgenus Rybonia 390 Subgenus Byronia 390 Subgenus Euilex 391 Subgenus Prinus 399 Taxonomic conclusions 399 Infiraspecific variabilityin 15 species of Ilex 400 Latitudinal and altitudinal trends; ecological and functional anatomy 402 Acknowledgements 404 References BLUMEA — VOL. No. 312 22, 3, 1975 Summary The ofleaf, node, twig, and bark of Phelline and Sphenostemonis anatomy Ilex, Nemopanthus, Oncotheca, , with wood of the latter Several characters recorded the described, together the anatomy 4 genera. are for first time. value of anatomical characters the wider affinities ofthe involved The systematic some for judging genera is discussed. Considering these characters together with macromorphological and palynological data, it is concluded that Phelline and Sphenostemon each merit family status, and have affinities with Aquifoliaceae and the Icacinaceae of the Celastrales. Oncotheca shows no affinities with families of Celastrales, and may possibly closest relatives but this has been studied detail. have its in Theales, problem not in great The leaf of Ilex and the leaf anatomical of Ilex is discussed anatomy 95 species is described, great diversity reference classification. with to Loesener’s infrageneric In general,leaf anatomy cannot be used to support his elaborate subdivision of the genus. Infraspecificleaf anatomical variability is reported and discussed for and functional 15 species of Ilex. Attention is paid to some geographical, ecological, aspects of the leaf anatomical of variation in Ilex. This has for leaf range range a general significance systematic anatomy, it because shows the restricted value ofseveral characters for the discussion ofaffinities above the genus level. Introduction Aims of this study The affinities of Sphenostemon from New Guinea, New Caledonia, and Queensland, and of Oncotheca from New Caledonia have been discussed and disputed over the last decades The inclusion of Phelline from Caledonia the in many publications. New in Aquifoliaceae has also been challenged by several authors. The three genera have in common that they have been mentionedrepeatedly in connection with the Aquifoliaceae. For the development of views the further collecting of more anatomical data on the two undisputed mem- bers of the Aquifoliaceae: Ilex and Nemopanthus, therefore seemed essential. With this aim anatomical Ilex in mind a detailed and elaborate survey of the wood range in has been in published (Baas, 1973); the present paper the leaf anatomy of Ilex will be treated in a similar the leaf and wood of way. Besides, anatomy Nemopanthus, Oncotheca, Phelline, and Sphenostemon will be comprehensively described, together with observations on nodal, bark It is considered data sounder twig, and anatomy. that these should provide a basis for anatomical comparison than the rather haphazard choice of miscellaneous species which the contributed to such diverse conclusions several authors. in past by Comparisons with other putative relatives will be based mainly on data from the literature, and will the with consequently suffer more from incompleteness than comparisons Aquifoliaceae sensu stricto. anatomical ofIlex should also be considered aim in itself. The leaf survey as an Although it will be attempted to find correlations with the infrageneric classification proposed by this aimed the Loesener (1901, 1908, and 1942), survey is mainly at determining leaf anatomical range in a large and widely distributed genus, and at indicating possibly useful characters for taxonomic which needed for this a future revision is badly genus. Historical views affinities As a starting point for a historical survey of on the ofIlex, Nemopanthus, and Loesener's and of the be Phelline, treatments (1901, 1908 1942) Aquifoliaceae can conveniently used; older literature is comprehensively listed by him. and differences The close affinities of Ilex Nemopanthus are beyond doubt; the only in P. Baas : Anatomy of Aquifoliaceae etc. 313 reduced and the free of external morphology are in the calyx in petals Nemopanthus as contrasted by the well-developed calyx and the at their base almost always more or less fused, imbricate petals of Ilex. treated Phelline characterized valvate Loesener in a separate tribe, by apiculate petals. Recently some doubts have been expressed about the inclusion ofPhelline in Aquifoliaceae. stated be On the grounds of pollen morphology Erdtman (1952) that arguments might advanced in favour of the assumption that Phelline has not yet been given its correct place referred in the system. Airy Shaw (1966, in Willis) doubtfully Phelline to Araliaceae (~ Aquifoliaceae) without giving further Takhtajan (1966) erected the family ’, arguments. Phellineaceae 'related to Aquifoliaceae, from which it differs, however, by having valvate petals, by the character of the inflorescence, the hemitropous or weakly campylotropous the wood the different and the leaf ovules, anatomy, quite sporoderm morphology, from Shaw venation' (quoted Takhtajan, 1969). His suggestion was followed by Airy in of corrected the latter the latest edition Willis' Dictionary (1973); the family name was by into Phellinaceae. When Baillon first he indicated links (1891) described the genus Oncotheca, with Phelline and Sphenostemon from the 'Ilicinees' and at the same time he suggested a relation- he the in in ship withEbenaceae. Later (1892) formally included genus Ilicaceae, his concept also including Cyrilla and Cliftonia, which are now in Cyrillaceae. Kronfeld (1892) in- of but cluded Oncotheca in his treatment the Aquifoliaceae, Loesener (1897, 1901, and 1942) in this and it Ebenaceae and never accepted the genus family assigned to (1897, 1942) also affinities with suggested Sapotaceae (1901). Guillaumin (1938) most strongly advocated the Ebenaceous nature of Oncotheca and formally erected the tribe Oncotheceae within Ebenaceae on the basis of both macromorphological and anatomical characters. More recently Airy Shaw (1965) erected the family Oncothecaceae, following unpublished Kobuski. An and suggestions by Ebenaceous affinity was suggested to be erroneous, with of affinities Theaceae were considered to be rather close. The pollen Oncotheca has not yet been properly described; Erdtman (1952) could only dispose of an inadequate slide ilicoid and be of of mixed smooth grains. Both types would, in any case, not suggestive Ebenaceous affinities. The exceedingly chaotic taxonomic history of the genus Sphenostemon (including and Bernardi Idenburgia Nouhuysia ) has been very comprehensively reviewed by (1964). of views With reference to his paper a survey the held before 1964 can be very brief. The reduction of Idenburgia Gibbs and Nouhuysia Lauterb. to Sphenostemon Baillon (Van affinities with Steenis, 1952, 1955) implies presumed Aquifoliaceae (Baillon, 1875; Van Steenis, 1955), with Trimeniaceae (Gibbs, 1917; Gilg & Schlechter, 1923), and with Guttiferae (Lauterbach, 1912; Van Steenis, 1952). Older views on the affinities of Spheno- the stemon sensu stricto had also differed: Loesener (1901, 1942) expelled genus from and Theaceous Ochnaceous Aquifoliaceae suggested a or affinity, leaving possibilities open for a Anatomical and contributions have far added separate family. palynological so only to the confusion: Money c.s. (1950), Bailey & Swamy (1953), and Bailey (1956) excluded Sphenostemon (Idenburgia and Nouhuysia) from Monimiaceae, Trimeniaceae, and Guttiferae, reluctant and Bailey (1956) was also to accept an Aquifoliaceous affinity. Previously had Money c.s. (1950) excluded Idenburgia from Monimiaceae on morphological grounds. Metcalfe's anatomical contribution(1956) to the problem also led him to conclude that it is that of is related evident none the genera ( Sphenostemon, Idenburgia, Nouhuysia) closely to either the Monimiaceae, Aquifoliaceae, or Guttiferae. The occurrence of styloid crystals mention in prompted him to a resemblance this respect with Escalloniaceae, without, however, implying and Escalloniaceous affinity for Sphenostemon s.l. Ingle & Dadswell 314 BLUMEA VOL. 22, No. 3, 1975 (1961) in comparing the wood of Nouhuysia (New Guineanand Australian Sphetiostemon) with that of Ilex, Platea (Icacinaceae), and Polyosma (Escalloniaceae) concluded that of these Ilex bears resemblance to that at genera least Nouhuysia,