HAMAMELIDAE

The Hamamelidae consist of 11 orders, 24 families and approximatley 3400 species. The Urticales have over two thirds of the species, with about one fourth of the Fagales. Most plants are woody, though some herbaceous taxa are present in the Urticles. Leaves are usually simple, less commonly compound. The flowers are generally reduced in size and moslty unisexualand monoecious (less commonly dioecious), with a poorly developed perianth (or lacking), and arranged in catkins. The anthers are large and produce large quantities of light, smooth pollen; wind pollinated. The female flowers usually produce few seeds per ovary. The fruit is an achene, nut, or samara.

Hamamelidales

PLATANACEAE

Deciduous trees; leaves alternate, simple, usually palmately lobed and veined, swollen petiole base covering axillary bud; speherical heads of unisexual flowers.

Genera: N.A.-1, IN-1

Platanus

Species: N.A.-4, IN-1

HAMAMELIDACEAE (26 genera; 100 species, subtropical and temperate)

Trees and shrubs; leaves usually alternate, simple or palmately lobed; flowers in heads or spikes; monoecious; sepals 4; petals none-4; stamesn 4 or more; pistils 2; inferior ovary with one locule.

Genera: N.A.-3, IN-2

Hamamelis #9; Liquidambar

Species: N.A.-5, IN-2

Urticales

Characteristics of the Urticales:

Leaves with with stipules (protect developing leaf)

Flowers unisexual, inconspicuous, but not in aments (catkins)

Perianth of tepals

Stamens opposite the tepals

Ovary 2-carpellate, one carpel often aborting, 1-loculate, with a single ovule

Fruit 1-seeded (achene, drupe or samara)

Mostly wind pollinated

ULMACEAE (18 genera; 150+ species; north temperate)

Trees or shrubs with watery sap; leaves simple, serrated with leaf bases oblique; superior ovary with one locule; fruit a one-seeded fruit an evenly winged samara or drupe.

Trees and shrubs

Leaves often with an oblique base

2 styles and stigmas

Ovule pendulous at apex of ovary

Genera: N.A.-5, IN-2

Ulmus Celtis

Species: N.A.-24, IN-8

CANNABACEAE

Differ from Moraceae in lacking milky latex and having flower parts in 5s instead of 4s.

Genera: N.A.-, IN-(2)

Cannabis Humulus

Species: N.A.-, IN-(3)

Trees, shrubs, rarely herbs, with milky sap; flowers unisexual; stigmas usually 2

Genera: N.A.-17, IN-2

Maclura Morus

Species: N.A.-31, IN-3

Mainly trees and shrubs

Prominent stipule scars (encircle stem)

Milky latex

Epidermis frequently with cystoliths

4 tepals (compare to Cannabaceae

2 styles and stigmas

Ovule pendulous

Fruit often multiple with perianth and/or inflorescence axis becoming fleshy (an accesory fruit)

URTICACEAE

Herbs with opposite or alternate leaves; some species with stinging haris; sepals 2-5; petals lacking; stamens 3-5; superior ovary with one locule.

Genera: N.A.-13, IN-5

Boehmeria Parietaria Pilea Urtica

Species: N.A.-72, IN-6

Mainly herbs or small shturbs

Stinging trichomes in some genera

Epidermis frequently with cystoliths

Filaments incurved in bud; flower opiening explosively, scattering pollen

1 style and stigma, the stigma brushlike

ovule basal

Juglandales

JUGLANDACEAE

Trees with alternate, pinnately compound leaves; pith of twigs chambered or continuous; staminate flowers in long slender catkins; pistillate flowers solitary, in small clusters, or in a spike; calyx of pistillate flowers regular and 3-5lobed, clayx of stminate flowers irregular; corolla absent; inferior ovry with 2-4 locules; fruit a nut enclosed by a woody husk.

Genera: N.A.-2, IN-2

Juglans Carya

Species: N.A.-21, IN-11

Fagales

FAGACEAE (6-8 genera; 800-1000 species ; cosmppolitan)

Trees and shrubs with laternate, simple leaves; stminate flwoers in drooping clusters; pistillate flowers solitary or few to a cluster; calyx 2-8lobed; corolla absent; stamens 3-20; ovary with 3-7 locules.

Genera: N.A.-5, IN-3

Castanea Fagus Quercus

Species: N.A.-88, IN-20

BETULACEAE (6 genera; 120-150 species,; cooler northern hemisphere)

Trees or shrubs with alternate simple leaves; monoecious; staminate flowers in catkins, pistillate flowers in spikes or scaly catikins; stamens 2-10; ovary with 2 locules.

Genera: N.A.-5, IN-5

Alnus Betula Carpinus Corylus Ostrya

Species: N.A.-33, IN-11