Maya V. Nilova

One-Seeded Fruits in the Core Caryophyllales: Their Origin and Structural Diversity

The core Caryophyllales consist of approximately 30 families (12 000 species) distributed worldwide. Many members evolved one-seeded or conjoined fruits, but their origin and structural diversity have not been investigated. A comparative anatomical investigation of the one-seeded fruits within the core Caryophyllales was conducted. The origin of the one-seeded fruits and the evolutionary reconstructions of some carpological characters were traced using a tree based on rbcl and matK data in order to understand the ancestral characters and their changes. The one-seeded fruit type is inferred to be an ancestral character state in core Caryophyllales, with a subsequent increase in the seed number seen in all major clades. Most representatives of the ‘Earlier Diverging’ clade are distinguished in various carpological traits. The organization of the pericarp is diverse in many groups, although fruits with a dry, many-layered pericarp, consisting of sclerenchyma as outer layers and a thin-walled parenchyma below, with seeds occupying a vertical embryo position, are likely ancestral character states in the core Caryophyllales clade. Several carpological peculiarities in fruit and seed structure were discovered in obligate one-seeded Achatocarpaceae, Chenopodiaceae, Nyctaginaceae, Seguieriaceae and Sarcobataceae. The horizontal embryo evolved in only certain groups of Chenopodiaceae. The bar-thickening of endotegmen cells appears to be an additional character typical of core Caryophyllales. The syncarpy-to-lysicarpy paradigm in Caryophyllaceae needs to be reinterpreted.

A new species of Arthrocnemum (Salicornioideae: Chenopodiaceae-Amaranthaceae) from West Africa, with a revised characterization of the genus

Abstract A new species Arthrocnemum franzii Sukhor. is described from the Republic of Cape Verde (Sal, Maio and Boa Vista islands). The species is recognized as distinct from Arthrocnemum macrostachyum (Moric.) K.Koch based on differences in the perianth shape, length of the anthers and style, and seed-coat ornamentation. No seed heteromorphism is observed within individuals of either species, despite differences in the size of the central and lateral flowers within each cyme (heteroanthocarpy). The North American Arthrocnemum subterminale (Parish) Standl. (syn. Salicornia subterminalis Parish) is morphologically distant from Eurasian Arthrocnemum or Salicornia/Sarcocornia group and should be excluded from these genera. The genus Arthrocnemum now comprises only two species (A. macrostachyum and A. franzii), distributed in the Mediterranean area, Macaronesia, West Tropical Africa and the Saharo-Arabian region. A generic description is here elaborated, clearly delimiting Arthrocnemum from morphologically similar species of Sarcocornia. A list of current species previously considered as Arthrocnemum is provided. It is argued that the taxonomic status of Salicornia mucronata Lag. (1817), mentioned in some references as a synonym of Salicornia macrostachya Moric. (1820) [≡Arthrocnemum macrostachyum (Moric.) K.Koch], is indeed a new synonym of Anabasis articulata (Forssk.) Moq. (subf. Salsoloideae). Both names merged with Arthrocnemum macrostachyum – Salicornia virginica Forssk. and Arthrocnemum glaucum (Delile) Ung.-Sternb. var. fasciculatum Sennen were lectotypified. The typification of the genus Arthrocnemum has so far been lacking and requires a special proposal with a conserved type.

Comparative bark anatomy of Bursaria, Hymenosporum and Pittosporum (Pittosporaceae)

Nilova, M. & Oskolski, A.A.: Comparative bark anatomy of Bursaria, Hymenosporum and Pittosporum (Pittosporaceae) — Plant Div. Evol. 128: 491–500. 2010. — ISSN 1869-6155. Bark anatomy in 3 species of Bursaria, 9 species of Pittosporum, and in the single species of monotypic genus Hymenosporum (Pittosporaceae) was examined. The members of these three genera resemble Araliaceae, Myodocarpaceae and Apiaceae in the occurrence of axial secretory canals in cortex and secondary phloem, the pattern of alternating zones in secondary phloem, and the absence of fibres in this tissue. We therefore confirm a relationship between Pittosporaceae and other Apiales (van Tieghem 1884, Dahlgren 1989, Takhtajan 1997, Plunkett et al. 1996, 2004) rather than its traditional placement into Rosales (Cronquist 1981). Hymenosporum differs markedly from Bursaria and Pittosporum in the presence of primary phloem fibres, in the cortical (vs subepidermal) initiation of the periderm and in the occurrence of numerous (more than 25) sieve areas on compound sieve plates. These features confirm the isolated position of Hymenosporum within Pittosporaceae, as suggested both by traditional taxonomy and gross morphology (Cayzer et al. 2000) and by molecular phylogenetics (Chandler et al. 2007).

Diagnostics, taxonomy, nomenclature and distribution of perennial Sesuvium (Aizoaceae) in Africa

Abstract The taxonomy of perennial Sesuvium species in Africa has been poorly investigated until now. Previously five perennial species of Sesuvium were recognised in Africa (S. congense, S. crithmoides, S. mesembryanthemoides, S. portulacastrum, and S. sesuvioides). Based on the differing number of stamens, S. ayresii is accepted here as being distinct from S. portulacastrum. Field observations in Angola also led the authors to conclude that S. crystallinum and S. mesembryanthemoides are conspecific with S. crithmoides. A new subspecies, Sesuvium portulacastrum subsp. persoonii, is described from West Africa (Cape Verde, Gambia, Guinea-Bissau, Mauritania, Senegal). The molecular phylogeny indicates the position of S. portulacastrum subsp. persoonii within the “American lineage” as a part of the Sesuvium portulacastrum complex which needs further studies. A diagnostic key and taxonomic notes are provided for the six perennial species of Sesuvium found in Africa and recognised by the authors (S. ayresii, S. congense, S. crithmoides, S. portulacastrum subsp. portulacastrum, S. portulacastrum subsp. persoonii, S. verrucosum and the facultatively short-lived S. sesuvioides). The distribution of S. crithmoides, previously considered to be endemic to Angola, is now confirmed for the seashores of Republic of Congo and DR Congo. The American species S. verrucosum is reported for the first time for Africa (the Macaronesian islands: Cape Verde and the Canaries). It is locally naturalised in Gran Canaria, being a potentially invasive species. These findings as well as new records of S. verrucosum from Asia and the Pacific Islands confirm its proneness to transcontinental introduction. Lectotypes of S. brevifolium, S. crithmoides, S. crystallinum and S. mesembryanthemoides are selected. The seed micromorphology and anatomy of the perennial African species is studied. Compared to the seeds of some annual African Sesuvium investigated earlier, those of perennial species are smooth or slightly alveolate. The aril is one-layered and parenchymatous in all species and usually tightly covers the seed. The aril detachments from the seed coat that form a white stripe near the cotyledon area easily distinguish S. verrucosum from other species under study.

Botany-collection.bio.msu.ru: Information system on plant morphology and anatomy

An open access information system (http://botany-collection.bio.msu.ru) consolidating digital data on palynological, carpological, and wood anatomy collections has been established at the Department of Higher Plants of the Faculty of Biology of Moscow State University. The database includes both digital images and short morphological descriptions of samples collected during the last 70 years. The system has a joint interactive catalogue of all samples included and allows a user to make a search by the names of species, genera, families, and life forms. In addition, each collection has a separate catalogue with various search parameters. The complete catalogues of all collections are also available in Excel file format.