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. 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). Samara.
U. parvifolia (Chinese elm). Beautiful bark on tree at Missouri Botanical Garden. Leaves and fruits. A bonsai specimen.
U. rubra (Slippery elm). Inflorescence. Flowers. Fruiting branch.

Planera

P. aquatica (Water Elm). Polygamomonoecious (as is Zelkova below). Line drawing (USDA Plants Database).

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.

Traditionally the genus Celtis (e.g. C. occidentalis - hackberry and C. laevigata - sugarberry) have been included in Ulmaceae. Molecular data (and your text) now place Celtis (and Trema) in Cannabaceae.

SIUC / College of Science / Elements of Plant Systematics
URL: http://www.plantbiology.siu.edu/PLB304/Lecture18Rosal/Ulmaceae.html
Last updated: 22-Mar-08 / dln