The genus Viola (Violaceae) is among the 40-50 largest genera among angiosperms, yet its taxonomy has not been revised for nearly a century. In the most recent revision, by Wilhelm Becker in 1925, the then-known 400 species were distributed among 14 sections and numerous unranked groups. Here, we provide an updated, comprehensive classification of the genus, based on data from phylogeny, morphology, chromosome counts, and ploidy, and based on modern principles of monophyly. The revision is presented as an annotated global checklist of accepted species of Viola , an updated multigene phylogenetic network and an ITS phylogeny with denser taxon sampling, a brief summary of the taxonomic changes from Becker's classification and their justification, a morphological binary key to the accepted subgenera, sections and subsections, and an account of each infrageneric subdivision with justifications for delimitation and rank including a description, a list of apomorphies, molecular phylogenies where possible or relevant, a distribution map, and a list of included species. We distribute the 664 species accepted by us into 2 subgenera, 31 sections, and 20 subsections. We erect one new subgenus of Viola (subg. Neoandinium , a replacement name for the illegitimate subg. Andinium ), six new sections (sect. Abyssinium , sect. Himalayum , sect. Melvio , sect. Nematocaulon , sect. Spathulidium , sect. Xanthidium ), and seven new subsections (subsect. Australasiaticae , subsect. Bulbosae , subsect. Clausenianae , subsect. Cleistogamae , subsect. Dispares , subsect. Formosanae , subsect. Pseudorupestres ). Evolution within the genus is discussed in light of biogeography, the fossil record, morphology, and particular traits. Viola is among very few temperate and widespread genera that originated in South America. The biggest identified knowledge gaps for Viola concern the South American taxa, for which basic knowledge from phylogeny, chromosome counts, and fossil data is virtually absent. Viola has also never been subject to comprehensive anatomical study. Studies into seed anatomy and morphology are required to understand the fossil record of the genus.

Makaleyi görüntüle

Essential oils from the subterranean organs of three species of Valeriana L. from Iran (Valeriana sisymbriifolia Vahl, Valeriana alliariifolia Adams and Valeriana officinalis L.) belonging to Valerianaceae family have been obtained by hydrodistillation and analysed by gas chromatography-mass spectrometry in order to discern the differences and similarities between the volatile chemical compositions of these species. More than 100 components were identified in essential oils of the studied plants (Supplementary Table S1--online only). The principal common constituents of the three species of Valeriana were spathulenol, limonene, γ-terpinene, vulgarone B and p-cymene. The main essential oil ingredients were α-selinene (7.83%) in V. sisymbriifolia, limonene (3.53%) in V. alliariifolia and spathulenol (13.33%), α-campholenal (11.48%), vulgarone B (8.38%) and valerenal (8.32%) in V. officinalis plants. Ageratochromene (precocene II), a chromene substance with antibacterial, antifungal, insecticidal and antijuvenile hormonal activities, was found at high levels (35.59% and 36.58%) in the essential oils of V. sisymbriifolia plants.

Makaleyi görüntüle

The volatile constituents of the essential oil of Valeriana alliariifolia Adams growing wild in Kurdistan, Iran were investigated by the GC and GC/MS techniques. Among the 26 compounds represented, 20 (96.3%) of them were identified as oil. The main components were: trans-caryophyllene (38.96%), beta-pinene (12.06%), alpha-pinene (9.94%), alpha-terpinene (9.49%), isoterpinolene (7.15%), 1,8-cineole (6.76%), 1-borneol (3.27%) and calarene (2.26%). Some of the physicochemical properties, such as the logarithm of calculated octanol-water partitioning coefficients (log K(ow)), total biodegradation (TB(d) in mol h(-1) and g h(-1)), water solubility (S(w), mg L(-1) per 25 degrees C) and median lethal concentration 50 (LC(50)) were calculated for the components 1-20 of V. alliariifolia Adams.

Makaleyi görüntüle

The native sum of valepotriates isolated from Val. alliariifolia Adams which was named valiracyl is an agent of low toxicity and exerts a pronounced neurotropic effect. Valiracyl suppresses the orientation reflex of animals in an "open field", decreases a spontaneous and caffeine-stimulated motor activity, potentiates and prolongs the action of barbiturates, significantly reduces aggressiveness of animals, decreases sensitivity to the convulsant effects of corasol and thiosemicarbazide, produces the antihypoxic and mild myorelaxant actions. The neurotropic effects of valiracyl are related to increased level of the GABA inhibition mediator and decreased intensity of bioenergetic processes in the brain.

Makaleyi görüntüle