Ulmaceae

Plant Sex: Flowers bisexual or unisexual (plants monoecious or polygamous).

Flowers: Actinomorphic, perianth reduced, not showy. Two-carpellate gynoecium with two styles but with one locule and one ovule.

Inflorescence: Flowers solitary or in cymes.

Fruits: Samaras (Ulmus) or nuts

Habit: Trees and shrubs

Leaves: Usually alternate, simple, doubly serrate, often with an oblique leaf base. Stipules present but early deciduous

Examples:

Ulmus

U. altata (Winged elm). Leafy branch. The corky wings on the branches give the plant its common name!
U. americana (American elm). A large tree near Grand Tower IL. Many American elms were killed by the Dutch Elm disease caused by a fungus (Ophiostoma ulmi). Branch showing floral and vegetative buds. Inflorescence. Flowers. Flower and flower dissected. Fruiting branch. Samara. Note the pubescent margin.
U. parvifolia (Chinese elm). Beautiful bark on tree at Missouri Botanical Garden. Leaves and fruits. A bonsai specimen.
U. rubra (Slippery elm). Leafy shoots. Samaras. Note the smooth margins.

Planera

P. aquatica (Water elm). Polygamomonoecious (as is Zelkova below). Leafy branch.

Zelkova

Z. serrata (Japanese zelkova). Shoots with staminate flowers at the base and carpellate flowers at the tip. Species is polygamomonoecious (trimonoecious). Staminate flowers. Carpellate (bisexual?) flowers. Young fruits.

CANNABACEAE includes not only Cannabis sativa (hemp or marijuana) and Humulus lupinus (hops), but also Celtis (e.g. C. occidentalis - hackberry and C. laevigata - sugarberry) and Trema. These plants have in the past been either in Moraceae or Ulmaceae.

SIUC / College of Science / Elements of Plant Systematics
URL: http://www.plantbiology.siu.edu/PLB304/Lecture18Rosal/Ulmaceae.html
Last updated: 01-Mar-09 / dln