Male flowers in fascicles arranged in erect spikes. Female flowers in clusters of 3, surrounded by an involucre. Filaments long. Styles 6, thread-shaped. Fruit enclosed in a prickly involucre. Leaves serrate.--Species 1 (_C. vulgaris_ Lam., chestnut). North-west Africa. Yields timber, bark for tanning, and edible fruits from which starch and oil are prepared. =Castanea= Tourn. Male flowers in simple, pendulous catkins. Female flowers each surrounded by an involucre. Filaments short. Styles 3, rarely 4-5, flattened. Fruit seated in a scaly, cup-shaped involucre.--Species 8. North-west Africa; one species also introduced into South Africa. They yield timber, cork, tanning and dyeing materials, chemical and medicinal drugs, starch, and fodder; some have edible fruits. “Oak.” =Quercus= L. ORDER URTICALES FAMILY 52. ULMACEAE Trees or shrubs. Juice not milky. Leaves simple, stipulate. Flowers axillary, solitary or in cymes. Perianth simple, with 3-8 segments. Stamens as many as and opposite the perianth-segments, rarely more, straight in the bud. Anthers opening by longitudinal slits. Ovary superior, 1-celled, very rarely (_Ulmus_) 2-celled. Ovule 1, pendulous, inverted. Styles or stigmas 1-2. Fruit a nut or a drupe. Seed with a membranous coat and with scanty albumen or without albumen.--Genera 5, species 35. (Under _URTICACEAE_.) (Plate 30.) 1. Stamens twice or thrice as many as the perianth-segments. Stigma 1. Flowers dioecious. Perianth much enlarged in fruit. Leaves opposite. Species 1. Abyssinia. [Subfamily =BARBEYOIDEAE=.] =Barbeya= Schweinf. Stamens as many as the perianth-segments. Stigmas 2. Flowers monoecious polygamous or hermaphrodite. Leaves alternate. 2 2. Fruit a compressed, winged nut. Embryo straight; cotyledons flat. Flower-clusters in the axils of scale-like bracts.--Species 1 (_U. campestris_ L., elm). North-west Africa. Yields timber, bast, tanning and dyeing materials, and medicaments. [Subfamily =ULMOIDEAE=.] =Ulmus= L. Fruit a more or less globular drupe. Embryo curved; cotyledons folded or rolled inwards. Flower-clusters or solitary flowers usually in the axils of the leaves. [Subfamily =CELTIDOIDEAE=.] 3 3. Stipules united. Leaves entire, penninerved. Spiny shrubs. Flowers unisexual. Perianth-segments of the male flowers valvate in the bud. Embryo with narrow cotyledons.--Species 4. Tropical and South Africa. =Chaetacme= Planch. & Harv. Stipules free. Leaves usually 3-nerved. Spineless shrubs or trees. Flowers usually polygamous. Perianth-segments imbricate in bud, at least at the apex. 4 4. Embryo with narrow cotyledons. Perianth-segments imbricate at the apex only. Flowers almost sessile.--Species 10. Tropical and South Africa. Some species yield timber, fibre, tanning and dyeing materials, and medicaments. (_Sponia_ Commers.) (Plate 30.) =Trema= Lour.