45- CASUARINACEAE — 46. PIPERACEAE — 47. SALICACEAE 161 



Genus i, species 2. Spontaneous in Madagascar and the neighbouring islands, 

 cultivated in other tropical countries. The wood (beaf-vvood) and the 

 bark are used, the latter for tanning and dyeing and in medicine. 



Casuarina Rumph. 

 ORDER PIPERALES 



FAMILY 46. PIPERACEAE 



Flowers in spikes. Perianth none. Stamens 2- — 6. Ovary i-celled. Ovule 

 I, basal, straight. Fruit a berry. Seed with a copious albumen and a small 

 embryo. — Genera 3, species 80. Tropical and South Africa. (Plate 27.) 



1. Stigma I, sometimes penicillate. Flowers hermaphrodite. Leaves ex- 



stipulate. Herbs. — Species 65. Tropical and South Africa. Some yield 

 vegetables or condiments or are used in medicine. 



Peperomia Ruiz & Pav. 



Stigmas 2 — 5. Leaves stipulate or sheathing at the base. Usually 



shrubs 2 



2. Flowers hei-maphrodite. Spikes axillary, arranged in an umbel. Stipules 



united into a sheath. Shrubs. — Species i. Tropics. Yields edible 

 fruits containing an aromatic oil and is also used in medicine. (Under 



Piper L.) Heckeria Kuntli 



Flowers unisexual or polygamous. Spikes leaf-opposed. — Species 17, 

 two of them only in cultiv^ation. Tropical and South Africa. Some 

 species yield spices (pepper) or are used in medicine. (Including Cocco- 

 bryon Klotzsch and Cubeba Miq.) (Plate 27.) Piper L. 



ORDER SALICALES 



FAMILY 47. SALICACEAE 



Trees or shrubs. Leaves alternate, entire toothed or lobed, stipulate. 

 Flowers in spikes or catkins, dioecious, without a perianth. Disc cup-shaped 

 or reduced to scales. Stamens 2 or more. Anthers opening by two longi- 

 tudinal slits. Ovary i-celled, with two or more parietal placentas. Ovules 

 inverted. Stigmas 2 — 4, sessile or nearly so. Fruit capsular. Seeds with a 

 basal tuft of hairs, without albumen ; embryo straight. — Genera 2, species 

 20. (Plate 28.) 



Disc cup- or urn-shaped. Stamens 4 — 30. Bracts jagged. Leaves, at 

 least those of the uppermost branches, broad (ovate or broader). 

 Buds terminal and lateral, covered by several scales. — Species 6. North 

 and East Africa. They yield timber, dyes, and medicaments. " Poplar." 



Populus L. 

 Disc reduced to one or several scales or teeth sometimes cohering at the 

 base. Bracts entire. Leaves narrow or rather broad (linear to ovate). 

 Buds lateral, covered by a single scale. — Species 15, two of them only 

 naturahzed. They yield timber, plaiting-, stuffing-, and tanning-materials, 

 and medicaments. " Willow." (Plate 28.) Salix L. 



