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Explore the Ulmaceae family, featuring trees and shrubs found in temperate regions worldwide. Learn about Ulmus (elms) and Celtis (hackberries) with unique leaf, flower, and fruit characteristics. Discover the economic importance and ecological role of these species.
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ANGIOSPERM FAMILIES 03 ULMACEAE THE ELM FAMILY
ULMACEAE • Trees and shrubs. • Widely distributed in the temperate regions of both hemispheres, with a few species in the tropics. • 18 genera and about 150 species. • Four genera in N America but only 2 are trees. • Ulmus - elms • Celtis - hackberries
CHARACTERISTICS OF THE FAMILY • HABIT: trees or shrubs. • LEAVES: alternate, simple, doubly serrate, short-petioled, uneven base, distichous (in one plane). • VENATION: pinnate and netted. • FRUIT: samara, drupe or nut.
DETAILS OF THE FLOWER • Anemophilous • Perfect • Borne on slender pedicels in fascicles or cymes. • Ovary flattened • Style 2-lobed • Flowers appear before leaves in the spring; some species flower in the summer or fall.
ULMUS AMERICANA FLOWERS FLOWERS PERFECT FRUIT - SAMARA ANTHERS PISTIL
CHARACTERISTICS OF THE GENUS ULMUS • LEAVES: oblong-obovate to elliptical; margin coarsely doubly serrate; apex acuminate; base conspicuously uneven; surface scabrous above, usually pubescent below. • FLOWER: in fascicles, on long pedicels; appearing before leaves in the spring. • FRUIT: oval to oblong obovate, deeply notched at the end; margins ciliate; a samara.
CHARACTERISTICS OF THE GENUS cont. • TWIGS: slender, zigzag (sympodial), brown, glabrous or slightly pubescent; lateral buds ovoid, acute but not sharp-pointed, slightly pubescent; chestnut brown. • Grows in forests, river bottoms, swamps, disturbed fields.
ULMUS CRASSIFOLIA Nutt.Cedar elm FRUITS - SAMARAS TWIG WITH CORKY OUTGROWTHS
LEAF COMPARISON ULMUS AMERICANA ULMUS CRASSIFOLIA
CHARACTERISTICS OF THE GENUS CELTIS L. • LEAVES: deciduous, alternate, distichous, single, simply serrate sometimes entire, base unevenly cuneate. • FLOWERS: perfect and imperfect (male, female and hermaphrodite flowers on the same plant – polygamo-monoecious); staminate flower flower borne below in fascicles; pistillate and perfect flowers above, singly in the leaf axils.
CHARACTERISTICS OF THE GENUS cont. • FRUIT: thick-skinned, thin-fleshed, ovoid or globose drupe; pit surface with a reticulate pattern. • TWIGS: slender, zigzag; pith terete, very finely chambered at the nodes, homogenous elsewhere; terminal buds lacking; lateral buds small, adpressed. • LEAF SCARS: 2-ranked, oval to crescent; bundle scars 3.
CELTIS LAEVIGATA WILLD.Sugarberry LEAF TWIG - SYMPODIAL
BARK AND FRUITS OF CELTIS sp. BARK OF C. OCCIDENTALIS FRUIT OF C. LAEVIGATA
ZELKOVA SERRATA, an ornamental elm from Japan, Taiwan and China
ECONOMIC IMPORTANCE OF THE ULMACEAE • Wood has commercial value. • Valuable ornamental trees used in parks and avenues. • The fruit of elms and hackberries are an important food source for wildlife. • Elms are susceptible to the Dutch Elm Disease.