Trees. Leaves alternate, unequally pinnate, without stipules. Flowers in spikes or catkins, monoecious, with bracteoles which are adnate to the ovary in the female flowers. Perianth 3-4-parted. Stamens numerous. Anthers opening by two longitudinal slits. Ovary inferior, 1-celled. Ovule 1, basal, straight. Styles 2, united at the base, stigmatose lengthwise. Fruit a drupe with an incompletely septate stone. Seed lobed, with a thin coat, without albumen. Genus 1, species 2. Cultivated in North Africa. They yield timber, tans and dyes, edible fruits (walnuts), oil, sugar, and medicaments. =Juglans= L. ORDER FAGALES FAMILY 50. BETULACEAE Trees or shrubs. Leaves alternate, undivided, stipulate. Flowers monoecious, in spikes or catkins, with a perianth of bract-like segments or without a perianth. Stamens 4. Ovary 2-celled at the base. Ovules solitary in each cell, descending, inverted. Styles 2. Fruit a nut. Seed 1, exalbuminous, with a membranous coat.--Genera 2, species 2. Extra-tropical regions. (Under _CUPULIFERAE_.) Male flowers without a perianth, with 2-parted filaments and hairy anthers. Female flowers with a small perianth and a jagged involucre free from the bract but adnate to the fruit. Fruit large. Female spikes bud-shaped, solitary. Leaves folded at the mid-rib in the bud.--Species 1 (_C. Avellana_ L., hazel). Cultivated and naturalized in North-west Africa. Fruits edible. [Tribe CORYLEAE.] =Corylus= Tourn. Male flowers with a 4-parted perianth, simple filaments, and glabrous anthers. Female flowers without a perianth, enclosed by a 5-parted involucre formed by the connate bracts and bracteoles. Fruit small. Female spikes cone-shaped, at length woody, arranged in racemes. Leaves [Illustration: MYRICACEAE. _FLOW. PL. AFR._ _Pl. 29._ J. Fleischmann del. Myrica conifera Burm. fil. _A_ Fruiting branch. _B_ Male inflorescence. _C_ Male flower. _D_ Group of fruits. _E_ Female flower. _F_ Ovary cut lengthwise. _G_ Fruit. _H_ Fruit cut lengthwise.] [Illustration: ULMACEAE. _FLOW. PL. AFR._ _Pl. 30._ J. Fleischmann del. Trema guineensis Schum. _A_ Flowering branch. _B_ Male flower cut lengthwise. _C_ Female flower cut lengthwise. _D_ Fruit cut lengthwise.] folded along the side-nerves in the bud.--Species 1 (_A. glutinosa_ 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-like, more or less united. Stamens 4-20. Ovary inferior, 3-6-celled at the base. Ovules 2 in each cell, descending, inverted. Styles 3-6. Fruit a nut surrounded by a cup-shaped involucre. Seeds without albumen.--Genera 2, species 9. Extra-tropical regions. (Under _CUPULIFERAE_.)