Ulmaceae (Elm family)

     [Latin name]
 
 

     18 Genera

     150 species (5 on campus)
 
 

I. Leaves

     A. Deciduous

     B. Alternate

     C. Simple

     D. Stipulate

     E. Pinnate venation

     F. Usually serrate/doubly serrate

     G. Usually inequilateral bases
 
 

II. Flowers

     A. Perfect or imperfect (monoecious)

     B. 4-6 stamens

     C. 1 celled ovary with 1 ovule, 2 styles
 
 

III. Fruit

     A. Samara, Drupe, Nut
 
 

IV. Economic importance

     A. Ornamental shade trees

     B. Wood has superior strength, toughness and bending qualities

          -> containers that are exposed to rough handling
 
 

V. Range

     A. Temperate regions of N. & S. hemispheres

     B. Few tropical speciesGeneric Comparison
 
 

I. Celtis (Hackberry)

     [Greek name]

     A. Serrate, often entire below middle

     B. Drupe

     C. 3 distinct veins at leaf base

     D. C. occidentalis (common hackberry) 

          [Western]
 
 

II. Zellkova

     [common name in Caucasus]

     A. Serrate

     B. Drupe

     C. 7 or more pairs of pinnate veins

     D. Zelkova serrata (Japanese zelkova)
 
 

III. Ulmus (Elms)

     A. Doubly serrate (most)

     B. Samara

     C. 7 or more pairs of pinnate veins

Species Comparison
 

I. U. americana (American Elm) 

     A. Leaves smooth or slightly pubescent

          if rubbed from apex to base

     B. Brown to reddish brown twigs

     C. Brown buds

     D. Very susceptible to Dutch Elm Disease (1930)
 
 

II. U. rubra (Red, Slippery Elm) 

     A. Leaves (15-20 cm) rough with scabrous pubescence

     B. Gray-brown pubescent twigs

     C. Black buds

     D. Brownish, furrowed bark

III. U. glabra (Scotch, wych Elm)

    A. Leaves (8-16 cm) rough with scabrous pubescence, often with 2 small lobes

     B. Gray-brown pubescent twigs

     C. Black buds

     D. Gray, smooth bark

     E. Camperdown elm is cultivar with pendulous branches grafted on short trunk
 

IV. U. parvifolia (Chinese Elm)

     [small flowered]

     A. Small leaves with single serrated margins

          and equilateral bases

     B. Puzzle shaped plates fall off to reveal orange

          inner bark on intermediate aged branches

     C. Flowers/Fruits in Fall


 

Moraceae (Mullberry Family)

     [Latin name]
 
 

     48 Genera

     1,000 species (2 on campus)
 
 

I. Leaves

     A. Alternate

     B. Simple

     C. Stipulate

     D. Latex
 
 

II. Flowers

     A. Imperfect (monoecious or dioecious)

     B. 4 sepals, 4 stamens

     C. 2-carpellate pistil
 
 

III. Fruit

     A. Usually multiple fruit of drupes or achenes
 
 

IV. Economic Importance

     A. Ornamental

     B. Edible fruit

     C. Asian silkworms feed on Morus leaves

     D. Latex for rubber from Ficus & Castilla
 
 

V. Range

     A. Mostly tropical with a few temperate species

Generic Comparison/Species Characteristics
 
 

I. Morus (Mulberry)

     A. Smooth (glabrous or slightly pubescent)

     B. Lustrous

     C. Elliptical, Lobed, especially juvenile, or unlobed

     D. Serrate

     E. Bark with yellowish tinge

     F. M. alba (White Mulberry)

          Introduced from China in failed attempt

          to establish Silk industry

     G. M. alba var. Tatarica (Russian Mulberry)

          1875 very hardy, red fruits
 
 

II. Maclura (Osage orange, Hedge apple)

     Monotypic M. pomifera  

     [apple bearing]
 
 

     A. Smooth

     B. Lustrous

     C. Oblong-lanceolate to ovate, Unlobed

     D. Entire

     E. Large spherical bright green multiple drupe

     F. Orange inner bark

     G. Yellow -> Orange wood from which yellow dye

          can be extracted with hot waterOrnamentals within the Florifera Apetalae
 
 

I. Eucommiaceae (Eucommia Family) 
 

     A. Eucommia ulmoides (Hardy Rubber Tree)

          Monotypic genus native to China

     B. Latex like Morus

     C. Imperfect flowers like Ulmus, but is dioecious

     D. Samaras like Ulmus

     E. Dark green rugose leaves
 
 

II. Cercidiphyllaceae (Katsura Tree Family) 
 

     A. Cercidiphyllum japonicum

          Monotypic genus native of E. Asia

     B. Crenate margins

     C. Opposite -> Subopposite -> Alternate

     D. Dioecious