Siphonodon

About: Siphonodon is a research topic. Over the lifetime, 8 publications have been published within this topic receiving 336 citations.

Phylogeny and Delimitation of the Celastrales Inferred from Nuclear and Plastid Genes

Abstract: A phylogenetic analysis of the Celastrales was performed using nuclear (18S, ITS 1, 26S rDNA) and plastid (atpB, matK, rbcL, trnL-F spacer) genes. In contrast to most previous studies, Celastrales and Malpighiales are resolved as being more closely related to one another than either are to Oxalidales. The Huaceae are well supported as the sister group to Oxalidales, not Celastrales, as had been previously proposed. The Lepidobotryaceae are unambiguously supported as sister to the clade consisting of Celastraceae and Parnassiaceae. The Parnassiaceae are well supported as members of an early branching lineage within Celastraceae, rather than as its sister group. Likewise, Pottingeria appears to be part of an early derived lineage of Celastraceae. Empleuridium is unambiguously supported as a derived member of Celastraceae, as are Brexia, Canotia, Siphonodon, Stackhousia, and Tripterococcus. Bhesa is unambiguously supported as a member of Malpighiales, though its relationships within the order remain...

Phylogeny of the Celastraceae inferred from phytochrome B gene sequence and morphology.

Abstract: Phylogenetic relationships within Celastraceae were inferred using a simultaneous analysis of 61 morphological characters and 1123 base pairs of phytochrome B exon 1 from the nuclear genome. No gaps were inferred, and the gene tree topology suggests that the primers were specific to a single locus that did not duplicate among the lineages sampled. This region of phytochrome B was most useful for examining relationships among closely related genera. Fifty-one species from 38 genera of Celastraceae were sampled. The Celastraceae sensu lato (including Hippocrateaceae) were resolved as a monophyletic group. Loesener’s subfamilies and tribes of Celastraceae were not supported. The Hippocrateaceae were resolved as a monophyletic group nested within a paraphyletic Celastraceae sensu stricto. Goupia was resolved as more closely related to Euphorbiaceae, Corynocarpaceae, and Linaceae than to Celastraceae. Plagiopteron (Flacourtiaceae) was resolved as the sister group of Hippocrateoideae. Brexia (Brexiaceae) was resolved as closely related to Elaeodendron and Pleurostylia. Canotia was resolved as the sister group of Acanthothamnus within Celastraceae. Perrottetia and Mortonia were resolved as the sister group of the rest of the Celastraceae. Siphonodon was resolved as a derived member of Celastraceae. Maytenus was resolved as three disparate groups, suggesting that this large genus needs to be recircumscribed.

Epidermal characters of the celastraceae sensu lato

Abstract: SUMMARY The leaf epidermal characters of 89 species belonging to 42 genera of the Celastraceae sensu lato (including Hippocrateaceae) are described in detail. The range and pattern of variation in stomatal type and presence and type of crystalliferous epidermal cells can be used to support the broad family concept of Celastraceae. The stomata may be anisocytic, complex anisocytic, anomocytic, cyclocytic, bi- and/or tricyclic, complex cyclocytic, laterocytic, complex laterocytic, paracytic, parallelocytic, helicocytic, or of an intermediate type. The laterocytic stomata are most common, and are here recognized for the first time as a distinct stomatal type characterized by the lateral position of the subsidiary cells (3 or more) but yet different from the paracytic and cyclocytic type. The general implications of the epidermal diversity for the grouping of genera in a natural classification are discussed. Special attention is devoted to the taxonomic position and/or delimitation of the following genera: Kokoona and Lophopetalum; Sarawakodendron; Perrottetia; Salada and the related genera Cheiloclinium, Peritassa and Tontelea; Hippocratea and the putatively related genera Antodon, Apodostigma, Cuervea, Elachyptera, Helictonema, Hemiangium, Hylenea, Loeseneriella, Prionostemma, Pristimera, Reissantia and Simirestis; Cassine sensu lato (including Elaeodendron, Crocoxylon and Mystroxylon); Denhamia and Maytenus; Euonymus; Goupia; Siphonodon and Pottingeria. Finally a tentative discussion of the wider affinities of Celastraceae is given and the scope for future studies is indicated.

Phylogeny of Celastraceae Subfamilies Cassinoideae and Tripterygioideae Inferred from Morphological Characters and Nuclear and Plastid Loci

Abstract: The phylogeny of Celastraceae subfamilies Cassinoideae (120 species in 17 genera in both the Old and New World tropics and subtropics) and Tripterygioideae (39 species in seven genera) was inferred using plastid (matK, trnL-F) and nuclear (ITS and 26S rDNA) loci together with morphological characters. Subfamily Cassinoideae include those Celastraceae genera with drupes, berries, or nuts that have one to five locules and one to two seeds per locule, while Tripterygioideae include those genera with one to two seeded samaras that lack arillate seeds. We infer that both subfamilies are grossly polyphyletic groups, with Cassinoideae consisting of ≥ eight separate lineages and Tripterygioideae consisting of ≥ six separate lineages. Crossopetalum, from tropical America, is part of an early derived lineage sister to a taxonomically diverse Austral-Pacific clade. Myginda is not distinct from Crossopetalum. Gyminda + Orthosphenia + Rzedowskia + Schaefferia are a clade that is only distantly related to Cros...