Unusual carpological characters in Marlothiella gummifera (Apiaceae)

AbstractFlowers and fruits of the monotypic Namibian endemic Marlothiella gummifera were examined to explore anatomical variation and to highlight problems associated with the homology of certain character states. Some unusual new features observed in the fruits and ovaries raise questions regarding the homology of fruit heteromorphy, rib oil ducts, vittae and carpophores in subfamily Apioideae. These include the irregular occurrence of heterocarpic ovaries, oil ducts on both the internal and external sides of the vascular bundles (the inner dwarf ducts), short ducts in the commissural area, and carpophores (only rarely present). The fruits of Marlothiella share several unusual features with the genus Lichtensteinia, namely concentric rings of cells around the rib oil ducts, of which the innermost are irregular in size and shape, very small vascular bundles that are usually comprised of two separate strands, and the occurrence of heteromorphy in fruits and ovaries. These two genera are morphologically very different and it is encouraging to find anatomical data to support their presumptive relationship based on molecular studies

Dichoropetalum schottii: examination of the type specimen, distribution and comparison with D. carvifolium-chabraei (Apiaceae)

The lectotype and isolectotype specimens of Peucedanum schottii, based on plants originally cultivated in Cremenets Botanical Garden, have been studied in detail. The geographic provenance of the plants is unknown but they are identical to natural populations in Albania, Bosnia & Herzegovina, Croatia, France, Greece, Italy, Montenegro and Serbia. The valid name for this plant is therefore Dichoropetalum schottii. It differs from a related species, D. carvifolium-chabraei, in having glabrous umbel rays, white (not yellow) petals, long styles and solitary secretory ducts in fruit valleculae

Fruit anatomy of the genus Bupleurum (Apiaceae) in northeastern China and notes on systematic implications

The fruit anatomy of all eight species of the genus Bupleurum L. mentioned in the most recent literature from northeastern China was studied for the first time. The eight species were divided into two groups based on the shape of the mericarps in transverse section. The first group (round mericarps without prominent ribs) includes B. longiradiatum and B. komarovianum, and the second group (angular mericarps with prominent ribs) includes B. angustissimum, B. bicaule, B. chinense, B. euphorbioides, B. scorzonerifolium and B. sibiricum. The second group can be further subdivided into group 2a (large vittae, very small vascular bundles) — B. euphorbioides and B. sibiricum, and group 2b (small vittae, large vascular bundles) — B. angustissimum, B. bicaule, B. chinense and B. scorzonerifolium. This result closely supports the traditional classification system which was based on gross morphology (plant height; leaf shape and size; involucre number, size and shape). The only exception is that B. komarovianum should not be close to the second group, but close to B. longiradiatum. Group 1 corresponds with Bupleurum sect. Longifolia and group 2 with sect. Eubupleura; group 2a with ser. Ranunculoides and group 2b with ser. Falcata. Fruit anatomical characters seem to have potential for evaluating infrageneric relationships in the genus Bupleurum

Using remote substituents to control solution structure and anion binding in lanthanide complexes.

A study of the anion-binding properties of three structurally related lanthanide complexes, which all contain chemically identical anion-binding motifs, has revealed dramatic differences in their anion affinity. These arise as a consequence of changes in the substitution pattern on the periphery of the molecule, at a substantial distance from the binding pocket. Herein, we explore these remote substituent effects and explain the observed behaviour through discussion of the way in which remote substituents can influence and control the global structure of a molecule through their demands upon conformational space. Peripheral modifications to a binuclear lanthanide motif derived from α,α′-bis(DO3 Ayl)-m-xylene are shown to result in dramatic changes to the binding constant for isophthalate. In this system, the parent compound displays considerable conformational flexibility, yet can be assumed to bind to isophthalate through a well-defined conformer. Addition of steric bulk remote from the binding site restricts conformational mobility, giving rise to an increase in binding constant on entropic grounds as long as the ideal binding conformation is not excluded from the available range of conformers