50. BETULACEAE - 51. FAGACEAE — 52. ULMACEAE 163 



folded along the side-nerves in the bud.— Species i (A. gliUinosa L., 

 alder). North-west Africa, also naturalized in South Africa. Yields 

 timber and bark for tanning. [Tribe BETULEAE.] Alnus Tourn. 



FAMILY 51. FAGACEAE 



Trees or shrubs. Leaves alternate, undivided lobed or pinnately cleft, 

 stipulate. Flowers in spikes or catkins, monoecious. Perianth-segments 4 — 7, 

 bract-hke, more or less united. Stamens 4 — 20. Ovary inferior, 3 — 6-celled 

 at the base. Ovules 2 in each cell, descending, inverted. Stades 3 — 6. Fruit 

 a nut surrounded by a cup-shaped involucre. Seeds without albumen. — 

 Genera 2, species g. Extra-tropical regions. (Under CUPULI FERAE.) 

 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 

 I (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, solitar}^ or in cymes. Perianth simple, with 3- — 8 segments. Stamens 

 as man}'- as and opposite the perianth-segments, rarely more, straight in the 

 bud. Anthers opening by longitudinal slits. Ovary superior, i-celled, very 

 rarely {Ulnius) 2-celled. Ovule i, pendulous, inverted. Styles or stigmas 

 I — 2. Fruit a nut or a drupe. Seed with a membranous coat and with scanty 

 albumen or without albumen. — Genera 5, species 35. (Under URTICA- 

 CEAE.) (Plate 30.) 

 I. Stamens twice or thrice as many as the perianth-segments. Stigma r. 

 Flowers dioecious. Perianth much enlarged in fruit. Leaves opposite 

 Species i. Abyssinia. [Subfamily BARBEYOIDEAE.] 



Barbeya Schwein t. 

 Stamens as many as the perianth-segments. Stigmas 2. Flowers monoe- 

 cious poh'gamous 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 i {U. cam- 

 festris L., elm). North-west Africa. Yields timber, bast, tanning and 

 dyeing materials, and medicaments. [Subfamily ULMOIDEAE.[ 



Ulmus L. 



