eISSN: 2357-044X Taeckholmia 36 (2016):115-135 Phenetic relationship between Malvaceae s.s. and its related families Eman M. Shamso* and Adel A. Khattab Department of Botany and Microbiology, Faculty of Science, Cairo University, Giza, Egypt. *Corresponding author:[email protected] Abstract Systematic relationships in the Malvaceae s.s. and allied families were studied on the basis of numerical analysis. 103 macro- and micro morphological attributes including vegetative parts, pollen grains and seeds of 64 taxa belonging to 32 genera of Malvaceae s.s. and allied families (Sterculiaceae, Tiliaceae, Bombacaceae) were scored and the UPGMA clustering analysis was applied to investigate the phenetic relationships and to clarify the circumscription. Four main clusters are recognized viz. Sterculiaceae s.s. cluster, Tiliaceae- Exemplars of Strerculiaceae cluster, Malvaceae s.s. cluster and Bombacaceae s.s. – Exemplars of Sterculiaceae and Malvaceae cluster. The results delimited Sterculiaceae s.s. and Tiliaceae s.s. to containing the genera previously included in tribes Sterculieae and Tilieae respectively; also confirmed and verified the segregation of Byttnerioideae of Sterculiaceae s.l. and Grewioideae of Tiliaceae s.l. to be treated as distinct families Byttneriaceae and Spermanniaceae respectively. Our analysis recommended the treatment of subfamilies Dombeyoideae, Bombacoideae and Malvoideae of Malvaceae s.l. as distinct families: Dombeyaceae, Bombacaceae s.s. and Malvaceae s.s. and the final placement of Gossypium and Hibiscus in either Malvaceae or Bombacaceae is uncertain, as well as the circumscription of Pterospermum is obscure thus further study is necessary for these genera. Key words: Byttneriaceae, Dombeyaceae, Phenetic relationship Spermanniaceae, Sterculiaceae s.s., Tiliaceae s.s. Introduction Malvales s.l. are a group of families Hibiscus (580, including Pavonia, etc.), of flowering plants estimated to contain 339 Sida (200), Abutilon (100), Dombeya (225), genera with 6133 known species Triumfetta (150, Grewia (290) (Stevens l.c.). (Christenhusz, and Byng, 2016) distributed Malvales can often be recognised by throughout the tropical and temperate regions spiral, pulvinate leaves that often have of both hemispheres, three families are palmate venation; stellate or fasciculate hairs endemics: Muntingiaceae (W Tropical or peltate scales, or less often with unicellular America), Sphaerosepalaceae and hairs, sometimes also with glands. Flowers Sarcolaenaceae (Madagascar) (Stevens 2001 in various types of basically cymose onwards 2014); the largest family is inflorescences, or less often solitary, mostly Malvaceae with 244 genera including 4225 bisexual, usually actinomorphic, 5-merous, species and the smallest Muntingiaceae commonly with a double perianth, often represented by 3 species belonging to 3 provided with an epicalyx. Petals free or genera (Christenhusz, and Byng, l.c.). sometimes basally adnate to the filament Members of this order contain many tube, contorted, imbricate or valvate, economically important taxa as fibers sometimes reduced; stamens basically in two (Gossypium); food and flavouring cycles, mostly five to very numerous, the (Theobroma cacao), wood plants (Tilia); as filaments usually connate into a tube. Fruits well as medicinal and ornamental garden usually dry, dehiscent or indehiscent, less plants (Simpson 2010). The largest genera in often fleshy, rarely winged, the capsule terms of number of species are sometimes muricate or spiny, and the seeds Received on 10/11/2016 and accepted on 28/12/2016 Eman M. Shamso and Adel A. Khattab or inside of the carpel walls are sometimes Bombacaceae. Hutchinson (1967) restricted conspicuously hairy. The bark is often very Malvales to include Malvaceae and fibrous and tough because of the stratified developed a new order Tiliales to include phloem. (Stevens 2001 onwards 2014; Tiliaceae, Bombacaceae and Sterculiaceae. Takhtajan 2009). Within the re-circumscribed Malvales were traditionally monophyletic order Malvales, Judd & circumscribed as four main families referred Manchster (1997), Bayer et al. (1999) and by many authors as"Core Malvales" viz.: APG II (2003) merged Tiliaceae, Bombacaceae, Sterculiaceae, Tiliaceae and Bombacaceae, Sterculiaceae with Malvaceae Malvaceae (Cronquist 1988; Takhtajan and subdivided the enlarged family 1997). Major disagreements existed between Malvaceae into nine subfamilies based on different taxonomic treatments and the molecular, morphological and bio- circumscriptions of these families and their geographical data: Byttneroideae (including systematic position have long been tribes Byttnerieae, Lasiopetaleae, problematic. A close relationship among Theobromeae and Hermannieae); these families, however, has generally been Grewioideae (including most genera of recognized since the time of Linnaeus (1753) former Tiliaceae); Tilioideae ( including both and was recently confirmed by Tilia and Craigia); Helicteroideae morphological, anatomical, chemical and (comprising most of the taxa previously molecular data (Chase et al. 1993, Soltis et included in Helictereae and Durioneae); al. 1997, Judd & Manchester 1997, Alverson Sterculioideae (including tribe Sterculieae); et al. 1998, Fay et al. 1998 and Bayer et al. Brownlowioideae; Dombeyoideae; 1999). Bombacoideae (corresponding to former Bentham & Hooker (1862) included Bombacaceae without Durioneae) and Malvaceae, Sterculiaceae and Tiliaceae in the Malvoideae (monophyletic but difficult to "cohort Malvales", and divided the order into delimit from Bombacoideae). three families: Malvaceae (incl. The ndhF cladogram of Alverson et al. Bombacaceae), Tliliaceae (incl. (1999) supported the monophyly of Elaeocarpaceae) and Sterculiaceae with traditional Malvaceae but the other three several tribes. traditional families are non-monophyletic; Schumann (1890-1897) separated and showed nine major lineages within three tribe Elaeocarpeae of Tiliaceae with some well-suported clades, labelled as subfamilies: genera and raised a separate family Malvoideae and Bomacoideae grouped in Elaeocarpaceae, accordingly, the order Malvatheca clade; Byttneroideae and Malvales consists of Tiliaceae, Sterculiaceae, Grewioideae grouped in Byttneriina clade; Malvaceae, Bombacaceae and Sterculioideae, Tilioideae, Helicteroideae, Elaeocarpaceae. The Elaeocarpaceae was Brownlowioideae and Dombeyoideae included in Tiliaceae by most authors grouped in Malvadendrina clade. (Kubitzki although it differ from the Tiliaceae and and Bayer 2003, Stevens 2001 onward, related families in the absence of stellate and 2014). peltate trichomes, the absence of mucilage Phylogenetic studies have shown the cavities or canals (Takhtajan 2009). Edlin core malvales constitute one of four major (1935 b) re-arranged the genera of Malvales clades within an expanded Malvales clade among families and recognized six families which also includes ten families: viz.: Scytopetalaceae, Tiliaceae, Neuradaceae, Thymelaeaceae, Sterculiaceae, Buettneriaceae, Bombacaceae Sphaerosepalaceae, Bixaceae, Cistaceae, and Malvaceae. The main chief of his system Sarcolaenaceae, Dipterocarpaceae, was the re-arrangement of the family Cytinaceae, Muntingiaceae, Malvaceae s.l. Sterculiaceae, so that it comprises only the (incl. Bombacaceae, Tiliaceae, Sterculiaceae, tribe Sterculieae while the tribe Hibisceae has Dombeyaceae and Byttneriaceae) distributed been transferred from the Malvaceae to the among seven monophyletic lineages Bombacaceae; three other genera of the (Alverson et al. 1998 & 1999, Fay et al. Malvaceae have been removed to the 1998, Bayer et al. 1999 and Kubitzki & 116 Phenetic relationship between Malvaceae s.s. Bayer 2003). All these families were Morphological characters previously considered to have malvalean observations: affinities in some traditional treatments (APG Appendix (2) shows the characters and III, 2009 & APG IV, 2016; Le Péchon character states scored for plant, pollen and & Gigord 2014, Stevens 2001 onwards 2014, seed morphology averaged for each OTU. In Shipunov 2016). The same concept was total 103 characters were taken into adopted by Reveal (2012) with slight consideration, comprising eighteen modification in which the order was quantitative and eighty-five qualitative expanded to include more than ten families. characters. Forty-five of the qualitative In Reveal’s system the Sterculiaceae, characters were scored as binary and the Tiliaceae, Bombaceaceae, Dombeyaceae and remaining were scored as multi-state Byttneriaceae were treated as separate characters. families. The recorded measurements of the whole The present study aims at applying plant and leaves were based on mature plant, numerical method for examining all flower descriptions were taken at anthesis morphological variation, inferring phenetic (if available) with the dimensions of sepals relationships among the examined taxa, and petals given in term of length (from base discussing the results obtained with recent to apex) x width (at the broader point), fruit classifications and confirming the position of and seed diameter included spines or wings ( the family Malvaceae s.s. and the allied if present). The data of pollen morphology families were mainly obtained from Erdtman 1952, Hosni & Araffa 1991, El Naggar 2004, Material and Methods Lakshmi 2003, El Husseini 2006, Perven et Plant materials: al. 2004, Perveen & Qaiser 2007, and Hamdy In the present study, sixty-four cultivated and & Shamso 2010. indigenous taxa belonging to thirty-two genera of four families