Rosales continued Diversity and Evolution of Rosids hemp figs and legumes Rhamnaceae buckthorns 52 genera 925 species of trees and shrubs in the tropics and temperate areas several genera have extensive radiations Phylica Phylica Rhamnus Ceanothus Ceanothus N2 fixing clade Rosaceae is sister to all other families of the order tendencies in rest of the order to loss of petals and shift to unisexual flowers with wind pollination or specialized insect pollination rose hops Rhamnaceae buckthorns 52 genera 925 species of trees and shrubs in the tropics and temperate areas many of our species are armed with thorns leaves are simple and alternate or opposite often with arcuate venation arcing along the edge and serrated edges Phylica Rhamnus Rhamnus cathartica European or common buckthorn invasive Rhamnaceae buckthorns CA 4 5 CO 4 5 A 4 5 G 3 flowers 4 or 5 merous 4 merous shown in common buckthorn stamens opposite the petals unusual in flowering plants Rhamnus cathartica European or common buckthorn Rhamnaceae buckthorns Rhamnus frangula Glossy buckthorn invasive Rhamnus alnifolia alder leaf buckthorn native Rhamnaceae buckthorns CA 4 5 CO 4 5 A 4 5 G 3 fruits one seeded drupes shrubs often confused with cherries and hollies Rhamnus cathartica European or common buckthorn Rhamnaceae buckthorns Ceanothus americanus New Jersey tea N2 fixing Elaeagnaceae Russian olive 3 genera 45 species of trees and shrubs largely in north temperate areas Elaeagnaceae Russian olive 3 genera 45 species of trees and shrubs largely in north temperate areas N2 fixing small trees and shrubs easily recognized by silvery or reddish glandular hairs covering bottom leaves and or stems Elaeagnus angustifolia Russian olive 4 merous flowers and berry fruits Shepherdia buffalo berry Elaeagnus angustifolia Russian olive Elaeagnaceae Russian olive Rosales Urticalean Families The remainder of the Rosales show the transition to reduced unisexual flowers and one seeded fruits Urticales Urticales Shepherdia canadensis buffalo berry Shepherdia argentea silver buffalo berry western N Am Buffalo berries are North American species with opposite leaves Ulmaceae elms Ulmaceae elms 6 genera 35 species of North Temperate trees Ulmus americana American elm best known for the American elm with its distinctive vase shaped growth form Dutch Elm disease caused by the fungus Ceratostomella umli umli has destroyed most large adults leaves are distichously arranged 2 ranks in one plane and pinnately veined leaf bases are strongly asymmetric Zelkova serrata European Ulmus americana American elm Ulmaceae elms CA 4 8 CO 0 A 4 8 G 2 flowers are bisexual but reduced and wind pollinated pollinated they appear before the leaves Ulmus americana American elm Ulmaceae elms CA 4 8 CO 0 A 4 8 G 2 pistil is made of two fused carpels but only one seed matures fruit is a samara a winged achene in this case Ulmus americana American elm Note 2 styles on samara Cannabaceae hackberry hops families Celtidaceae hackberry and Cannabaceae hops hemp are now merged into one Cannabaceae with 11 genera and 170 species Cannabaceae hackberry hops Celtis hackberries and relatives are tropical and temperate small trees with unisexual flowers leaves are strongly palmi pinnate with 3 main veins at base this leaf features defines all the other remaining urticalean families Cannabaceae first of the unisexual flowered lineages within Rosales Celtis occidentalis hackberry Cannabaceae hackberry hops Cannabaceae hackberry hops note distinctive warty bark Cannabis with one species is a coarse herb native to Eurasia fruit is a one seeded drupe two subspecies are recognized one the source of the drug 9 tetrahydrocannibol THC THC and the other the source of hemp fiber oil Celtis occidentalis hackberry Cannabis sativa Hemp marijuana hemp rope manila rope Cannabaceae hackberry hops Cannabaceae hackberry hops Cannabis is either dioecious or monoecious Cannabis sativa Hemp marijuana Female inflorescence Seeds 1 seeded Male inflorescence Cannabaceae hackberry hops Cannabis sativa L fiber oil cultivar subsp sativa var sativa var spontanea weakly intoxicant strongly intoxicant domesticate domesticate narcotic cultivar wild wild subsp indica var indica Cannabis sativa is in all legal statutes not C indica indica var kafiristanica A practical and natural taxonomy for Cannabis Cannabis Small Cronquist 1976 Cannabaceae hackberry hops JJ Forensic Forensic Sci Sci 1976 1976 Apr 21 2 239 51 Apr 21 2 239 51 The The forensic forensic taxonomic taxonomic debate debate on on Cannabis Cannabis semantic semantic hokum hokum Small Small E E It It has has been been asserted asserted that that there there are are legal legal species species of of marihuana marihuana plants plants and and this this contention contention has has generated generated frequent frequent court court challenges challenges of of criminal criminal prosecutions prosecutions involving involving marihuana marihuana Invariably Invariably the the claim claim is is made made that that the the name name C C sativa sativa used used in in legislation legislation is is insufficiently insufficiently comprehensive comprehensive to to proscribe proscribe all all forms forms of of marihuana marihuana The The maneuver maneuver being being used used alarmingly alarmingly is is potentially potentially applicable applicable to to innumerable innumerable other other materials materials but but its its success success is is based on a failure to appreciate the subjective nature of taxonomy and the based on a failure to appreciate the subjective nature of taxonomy and the little known little known but but critical critical ambiguities ambiguities which which are are inherent inherent in in scientific scientific names names The The complex complex principles principles and and operational operational conventions conventions of of biological biological nomenclature nomenclature are are presented presented in in elementary elementary fashion fashion Despite Despite important important technical technical constraints constraints on on the the use use of of scientific scientific names names some some facts facts are clear these names are used subjectively they may be highly ambiguous are clear these names are used subjectively they may be highly ambiguous the the consensus consensus on on use use of of these these names names is is liable liable to to change change with with time time and and most most important important quite quite permissibly