Taxonomic studies in the genus Scrophularia

Abstract

The study is divided into 2 parts: part one deals with the reclassification of the genus, nomenclature, and the investigation of taxonomic characters.The author has accepted two sections, Ceramanthe and Scrophularia. Sect. Ceramanthe is divided into 3 subsections, namely Graciles, Orientales and Vernales, and sect. Scrophularia into 6 subsections, namely Heucheriflorae, Subaequilobae, Przewalskiae, Farinosae, Caninae and Lepidotae. He recognises 5 series within subsect. Vernales and 11 in subsect. Caninae.The sections, subsections and the series have been described, their distribution discussed, and a key, a synopsis of infra -generic taxa, and distributional maps have been provided.There appears to be 2 centres of morphological diversity of the genus: 1) C. Asia and 2) S.Y. Asia (Turkey, Caucasia, Iran, Iraq, etc.). The maximum morphological diversity has occurred in S.W. Asia and it is also interesting to note that about 2 /3rd of the total number of species tend to be concentrated in this area.Staminode shape and leaf anastomosis, which have been used in the past to delimit the sections have been found to be unreliable. The relative length of the upper corolla lobes, which is correlated with the presence or absence of a staminode, have proved to be the most useful in the delimitation of the sections. Ventricose /cylindrical corolla together with its glabrous or glandular condition, leaf arrangement, and indumentum have been used as the principal diagnostic for separating the subsections. The series are mostly separated on the basis of a number of correlated differential characters. The morphological characters used in the classification have been illustrated, their taxonomic usefulness assessed and evolutionary trends have been discussed.Apart from 2 types of stem cortices (with or without palisade), which has been used in the delimitation of series Leucocladae, anatomy offers little aid in classification.Developmental studies have been carried out with regard to the following organs; stomata, indumentum, cymes, scarious margin of calyx segments, corolla lobes, staminode and stigma. Developmental studies explain at least in part the staminode variability. Due to the significant intra -, and interspecific variability, the use of the staminode shape has been avoided in the classification presented here. Evolutionary trends in the corolla lobes and staminode shape are discussed.The chromosome number has been determined for the first time in 5 species and confirmed in 3 species. Camera -lucida drawings of chromosomes and a few photographs are presented. The relationship of cytology to morphology, taxonomy, distribution, etc. is discussed.Part 2 deals with a detailed revision of the Turkish species (including those from the Aegean islands). S. heterophylla has been excluded from the area, but the following 14 species have been added to the Turkish list: S. zuvandica, S. thesioides, S. striata, S. kurdica, S. amplexicaulis, S. scariosa: puutìlicz,, S. arcana, S. bitlisica, S. serratifolia, S. gypsicola, S. davisii, S. subaequiloba, S. mersinensis; the last 8 of these are described here as new to science. The revised list (with several previously accepted species reduced to synonomy or infra -specific rank) now comprises 49 species.The original descriptions of the species have been amplified on the basis of the material seen. A key and a synopsis of classification is also provided. The staminode is drawn for nearly all the Turkish and a few non -Turkish species. All the Turkish species are assigned to their phytogeographical regions, their distribution is given and distributional maps are also provided.Out of 1+9 species, 21 are endemic to Turkey. The percentage of endemism is )j /o for the species, and l4ó for species, subspecies and varieties. Most of the endemics tend to be concentrated in E. & S. Anatolia; areas of rugged topography and mountain ranges seem to have been the active centres of speciation. The relationship of the endemics are discussed and their distribution is shown.The thesis has been illustrated with 17 figures and 21 plates. An index to the species is provided.