Floral structure and development of Ceratiosicyos laevis (Achariaceae) and its systematic positionBERNHARD, A.
doi: 10.1111/j.1095-8339.1999.tb01843.xpmid: N/A
AbstractThe morphology and development of the flowers of Ceratiosicyos laevis (Achariaceae) were investigated. Plants are monoecious and the inflorescence is a thyrse composed of a single female flower and two male cymose partial inflorescences. The sympetalous flowers of both sexes have an unusual urceolate shape. In young buds the free parts of the petals are postgenitally united. Before anthesis the fusion is ruptured but the petals remain coherent due to marginal cilia. Nectary-like bodies situated at the floral base seem to stabilize the shape of the flower additionally. The anthers are coherent by interlocking epidermal cells and form a narrow tube. They lack an endothecium. In anthesis only the style and the anther tube respectively protrude out of the flower. The synorganization of the anthers, the powdery pollen and the lack of an endothecium are suggestive of a buzz pollination syndrome. Some characters point to an affinity of Achariaceae with Cucurbitaceae. However, the family seems to be more closely related to Passifloraceae.
Anatomy and morphology of Behnia (Behniaceae) and its relationships within Lilianae: AsparagalesCONRAN, JOHN G.
doi: 10.1111/j.1095-8339.1999.tb01844.xpmid: N/A
AbstractThe vegetative and floral anatomy, morphology, embryology and seedlings of Behnia reticulata (Thunb.) Didr. are described, and the relationships of the recently described endemic southern African monocot family Behniaceae Reveal are discussed. Recent molecular studies place the family with the Agavaceae, Hostaceae, Anthericaceae, Herreriaceae and Ane-marrhenaceae. Behnia shows some morphological similarities with this clade, such as the woody shrub habit, a secondary thickening meristem in the rhizomes, small flowers and baccate fruits; but differs in several features, such as reticulate leaf venation, cryptodioecious flowers and seeds lacking phytomelan. Embryologically, the Behniaceae agree with the other members of their clade, although there are no clear synapomorphies by which the group may be defined from other Asparagalean clades.
A revised classification of CryptophytaCLAY, BREC L.; KUGRENS, PAUL; LEE, ROBERT E.
doi: 10.1111/j.1095-8339.1999.tb01845.xpmid: N/A
AbstractThe systematics of currently recognized cryptomonad genera is reviewed. Complete ultra-structural descriptions are provided for each genus, and are based on the most recent observations in the literature. Using ultrastructural, biochemical and molecular data, a classification scheme, which delineates 16 genera, is proposed for the Cryptophyta. This scheme accommodates two classes, the Cryptophyceae and the Goniomonadea. These differ primarily in that the former possesses a plastidial complex whereas the latter lacks one. Three orders are discussed and are separated on the basis of colour. The order Conio-monadales, which consists of a single genus, is aplastidal and colourless. The order Crypto-monadales has two families and contains the accessory pigment Cr-phycoerythrin 566 which imparts a brown colour to the cells. The constituent families, Cryptomonadaceae and Campylomonadaceae, are separated by variations in the furrow/gullet complex, the inner periplast component (IPC), nucleomorph position, and the type of rhizostyle. The order Pyrenomonadales contains four families. It is the sister group to the Cryptomonadales and possesses the accessory pigments Cr-phycoerythrin 545, 555, and these impart a red colour to the cells, or other members that possess Cr-phycocyanin 630, 645, or 569, which impart a blue-green colour to the cells. The four families are separated on the basis of phycobiliprotein type and, where appropriate, a combination of nucleomorph placement, type of IPC, rhizostyle type, and furrow plate type. This scheme accommodates three new families, the Campylomonadaceae, Geminigeraceae, and Chroomonadaceae.
Taxonomic notes on Polygonaceae from southern tropical AfricaORTIZ, SANTIAGO; PAIVA, JORGE A. R.
doi: 10.1111/j.1095-8339.1999.tb01847.xpmid: N/A
AbstractAs part of taxonomic studies of the family Polygonaceae for the Flora Zambesiaca project, two new species from southern tropical Africa are described: Persicaria nogueirae S. Ortiz & Paiva, from Zambia and Angola, and Oxygonum annuum S. Ortiz & Paiva, from Zambia. In addition, two new combinations are proposed: Polygonum glomeratum Dammer is transferred to the genus Persicaria as Persicaria glomerata (Dammer) S. Ortiz & Paiva, and Persicaria attenuata (R. Br.) Soják subsp. africana K.L. Wilson is renamed Persicaria madagascariensis (Meisn.) S. Ortiz & Paiva.
Hybridization between Fagopyrum (Polygonaceae) species native to ChinaCHEN, QING-FU
doi: 10.1111/j.1095-8339.1999.tb01848.xpmid: N/A
AbstractThirty-eight crosses between seven Fagopyrum species native to China were studied. Following normal pollination, there were very low inter-group crossabilities (only 0 3%) between five species in the large-achene group and two species (E gracilipes and E pleioramosum) in the small-achene group, and high (15 50%) within the large-achene group, i.e. E esculentum, E tataricum, E zuogongense, E pilus and E megaspartanium. Crosses between various types of (lowers (homostyle, heterostyle etc.) suggested that the intraspecific incompatibility also occurs in interspecific crosses. The hybrid seeds obtained from interspecific crosses all withered or shrivelled and lacked activity. Only one hybrid plant was obtained, tetraploid E esculentum x tetraploid E zuogongense. The hybrid displayed anomalous behaviour at meiosis, pollen grain sterility and withering of achenes, confirming the genetic differences between E esculentum and E zuogongense. The results support the hypothesis that E megaspartanium and E pilus are the possible ancestors of cultivated buckwheat
Allozymic variation and divergence in three species of Antirrhinum L. (Scrophulariaceae-Antirrhineae)MATEU-ANDRÉS, ISABEL
doi: 10.1111/j.1095-8339.1999.tb01849.xpmid: N/A
AbstractAn allozymic study of three wild species of Antirrhinum L. A. lopesiamum Rothm., A. mollissimum Roihni. and A. microphyllum Rothm. is described. All are members of subsection Kickiella Rothm., and are narrow-range endemics of the Iberian Peninsula. The variability of the different loci, as well as the number and mobility of the alleles, differ among the three species, a demonstration of the usefulness of allozymes for the systematics of the genus. The finding of alleles unique to each species indicates high divergence among species suggesting ancient diversification, and supports the hypothesis of a geographical model of speciation. All three species show high levels of within-species variability, mainly partitioned within populations, while between populations genetic differentiation is low. Correlations between population size, sample size and genetic variability, and the usefulness of allozymic data for conservation purposes, are discussed.