Skiatophytum LBolus
Country Life 17 435 (1927). Annual to short-lived perennial with a rosette, forming elongate branches later. Leaves decussate, but later alternate, margins undulate when young. Flowers in moderate terminal dichasia petals white, margins papillate. Capsule 5-locular with a parietal placenta and upper-distal seed chambers the valves opening xerochastically in their proximal part only dispersal as a tumble fruit and by scattering. One sp., SW part of S Africa.
Flowering Plants Dicotyledons
Magnoliid, Hamamelid and Caryophyllid Families K. Kubitzki J. G. RohweM . Bittrich (Eds.) THE FAMILIES AND GENERA OF VASCULAR PLANTS Volume I Pteridophytes and Gymnosperms Edited by K.U.Kramer and P.S.Green (1990) Volume II Flowering Plants Dicotyledons Edited by K. Kubitzki, J. G. Rohwer, and V. Bittrich (1993) The Families and Genera of Vascular Plants
Current Trends in the Study of Angiosperms
The angiosperms are the largest, most highly diversified, and most successful major group of land plants. They contain an estimated 225000 to 350000 species, some 12000 to 13000 genera, and 250 to more than 500 families, depending on the taxonomic concepts applied. In retrospect, it is most surprising that the general outline of their classification had already been recognized by the time of Bentham, more than a century ago. Many elements of this classification have not only been incorporated...
Haniamelid Families
It is now generally accepted that the floral structure in the catkin-bearing Amentiferae is secondarily simplified in adaptation to anemophily. The development of a concept of a woody, predominantly anemo-philous clade6 has led to the exclusion of various alien elements and the inclusion of the partly insect-pollinated, nectariferous Trochodendrales and Hama-melidales. It is often thought that these remodeled Hamamelididae form a largely coherent group but this is not universally accepted, as...
Bittrich And Kuhn In Kubitzki
This volume - the first of this series dealing with angiosperms - comprises the treatments of 73 families, representing three major blocks of the dicotyledons magnoliids, centrosperms, and hamamelids. These blocks are generally recognized as subclasses in modern textbooks and works of reference. We consider them a convenient means for structuring the hundreds of dicotyledon families, but are far from taking them at face value for biological, let alone mono-phyletic entities. Angiosperm taxa...
Habitat Adaptations
The striking fact that arid or semi-arid environments provide appropriate habitats for members of the order was mentioned by various authors. A common adaptation to arid conditions are succulent leaves e.g., Aizoaceae, Chenopodiaceae, and Portulacaceae and or stems. Succulent stems are often photo-synthetically active, sometimes combined with a more or less strong reduction of the leaves Cac taceae, Didiereaceae, and Chenopodiaceae . Succulence can be combined with Crassulacean Acid Metabolism...
Aizoon L
PI. 488 1753 Adamson, J. S. Afr. Bot. 25 29-50 1959 . Dead remains of plants sometimes persisting over several years, all parts hairy. Leaves often crowded, petiolate or sessile, flat to cylindrical. Inflorescence mostly frondose, flowers often seemingly solitary or in seemingly axillary groups, interior of perianth white, yellow, or pink stamens few to many, filaments filiform. Fruit with a central impression, expanding keels short, lifting the valves only slightly, or long....
Introduction to Centrospermae
The Caryophyllales or Centrospermae Eichler 1878 are a good, if not the best, example of a major natural group within the angiosperms. First recognized by Bartling 1830 as Caryophyllinae, it is accepted at present in nearly the same circumscription as in Braun's treatment 1864 see Table 1 . The most useful characters for the order known at that time were the so-called free-central placentation, the mostly campylotropous ovule e.g., Hofmeister 1858 , and the presence of perisperm e.g., Schleiden...
Magnoliid Families
Magnoliid or ranalean families comprising the subclass Magnoliidae in the sense of Cronquist, or the subclasses Magnoliidae plus Ranunculidae in the sense of Takhtajan have received foremost attention by botanists because they are believed to represent the most primitive group of extant angiosperms. Since the time of Arber and Parkin 1907 , the flower of Magnolia has been viewed as the archetype of an angiosperm flower. The work of Bailey and his coworkers on the morphology and relationships of...
Relationships of the Centrospermae
In the past, most systematists accepted the Polygona-ceae occasionally also the Plumbaginaceae as the closest relatives of the Centrospermae. This idea had already been suggested by R. Brown 1810 , based on similarities such as the uniseriate perianth, the unilocular ovary, the single ovule, and the basal placenta. However, the unilocular and uniovulate ovary has probably evolved within the Centrospermae and is therefore no proof of a common descent with the Polygonales. On the other hand, some...
Block
Evolutionary advance of dicotyledons is accompanied by increase in the relative importance of flavones over flavonols BateSmith 1962 , by decrease in the incidence of proanthocyanidins and, according to postulates of more general validity, by increase in mean oxidation level of the compounds pertaining to a biosynthetic class and by decrease in lignification Gottlieb 1982,1989, 1990 . In respect to all these concepts, the flavonoid data registered in Table 2a, b,...
General References
Histoire des plantes, 13 vols. Paris L. Hachette et Cie. Bentham, G., Hooker, J.D. 1862-1883. Genera Plantarum, 3 vols. London various publishers. Cronquist, A. 1968. The evolution and classification of flowering plants. London Nelson. Cronquist, A. 1981. An integrated system of classification of flowering plants. New York Columbia University Press. Cronquist, A. 1988. The evolution and classification of flowering plants, 2nd edn. New York The New York Botanical Garden....
Systematic Evidence
Embryological characters were of utmost importance in the early attempts to circumscribe the Centrospermae and to confirm the inclusion of the controversial Cactaceae Hofmeister 1858 Rocen 1927 Mauritzon 1934 Neumann 1935 . The most important and probably derived embryo-logical characters are the 3-celled pollen grains, the curved ovules and embryos, the dermal derivation of the outer integument, the transient airspace between the integuments not observed in Caryophyllaceae yet ,...
Plinthus Fenzl
Vindob. Dec. 51 1839 Ver-doorn, Bothalia 4 177-179 1941 Adamson, J. S. Afr. Bot. 27 147-151 1961 . 1. Gunniopsis Pax in Engler amp Prantl Gunniopsis Pax in Engler amp Prantl, Nat. Pfl. fam. Ill, lb 44 1894 Chinnock, J. Adel. Bot. Gard. 6 133-179 1983 . A iz ooraL. subg. Gunniopsis Pax amp Hoffmann Adamson 1959 . Herbs to woody shrubs. Leaves opposite, linear-terete, flat or oblanceolate, papillate to smooth, with multiseriate hairs ending in a conspicuous apical...
Kubitzki J G Rohwer and V Bittrich With Figures
Springer-Verlag Berlin Heidelberg New York London Paris Tokyo Hong Kong Barcelona Budapest Professor Dr. Klaus Kubitzki Institut f r Allgemeine Botanik und Botanischer Garten Ohnhorststra e 18 22609 Hamburg, Germany Dr. Jens G. Rohwer Institut f r Systematische Botanik und Pflanzengeographie Im Neuenheimer Feld 345 69120 Heidelberg, Germany Dr. Volker Bittrich Institut f r Allgemeine Botanik und Botanischer Garten Ohnhorststra e 18 22609 Hamburg, Germany ISBN 3-540-55509-9 Springer-Verlag...
Relationship within the Centrospermae
As discussed above, a convincing phylogenetic analysis of the Centrospermae is still hardly possible. The monophyly of several families is at least doubtful see Carolin 1983 Brown and Varadarajan 1985 Rogers 1985 Carolin 1987 Bittrich and Hartmann 1988 Hershkovitz 1989 and contributions in this Volume . This applies to the - Amaranthaceae and Chenopodiaceae unclear delimitation of both families, especially with regard to tribe Polycnemeae - Molluginaceae characterized by ancestral characters...
Phylogenetic Relationships Among Major Angiosperm Groups
Despite much effort that has been devoted to resolving the phylogenetic interrelationships among major groups of angiosperms, this is still a controversial issue. The monocot hypothesis of Burger 1981 , based on vegetative similarities between pterido-phytes and monocotyledons, and claiming the primacy of monocotyledons in angiosperm evolution, has found no support at all. The ranalean hypothesis, according to which the magnoliids are the direct ancestor of the monocotyledons and dicotyledons,...
Subfam Aizooideae
Inflorescence leafy perianth internally petaloid, externally sepaloid flower perigynous or very rarely hypogynous capsule loculicidal or septicidal, often hygrochastic x 8. Six genera, mainly in S Africa and Australia, in E Africa and the Mediterranean, introduced worldwide into suitable climates, mainly as weeds in arid country. Key to the Genera of Subfamily Aizooideae. 1. Fruit a purely septicidal or septicidal loculicidal hygrochastic capsule 1. Gunniopsis - Fruit a purely loculicidal...
Achatocarpaceae
Achatocarpaceae Heimerl in E.-P., Nat. Pflanzenfam. ed. 2,16c Dioecious trees or shrubs, sometimes thorny. Leaves alternate, simple, entire, exstipulate. Flowers small, hypogynous, in axillary racemes or panicles, brac-teoles present or absent sepals 4-5 petals none stamens 10-20, filaments distinct or connate at base ovary bicarpellate, unilocular with one basal ovule styles two fruit a berry seeds with an annular embryo surrounding the perisperm. A poorly known family of two genera and ca....
Aizoaceae
Veg. 53 1830 nom. cons. Predominantly succulent, annual to perennial herbs, subshrubs or shrubs. Leaves mostly opposite, simple and entire, epidermis with bladder idioblasts, or uniform and xeromorphic, often pubescent base of petioles rarely with stipuliform appendages or leaves sessile with a connate leaf sheath. Cymose inflorescences of principally dichasial pattern complete or in various derived forms, mostly terminal, often seem- Kg.3A-D. Aizoaceae. Growth...
