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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
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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.