BINDWEEDS 405 



both /. Batatas and /. hederacea (formerly called /. 71U) were growing 

 in England. The genus is rich in drug-producing plants, and doubtless 

 several species owe their early introduction to this fact. /. Batatas is 

 the Sweet Potato, whose tuberous roots are largely used in the Tropics 

 for food. It is believed to have been known in this country long before 

 the introduction of the now common Potato by Sir Walter Kaleigh. The 

 word Potato is said to be a corruption of Batatas. Many species possess 

 a milky juice whose properties are of a purgative character, and from 

 which inferior kinds of Jalap and Scammony are prepared. The real 

 Jalap is produced by /. purga, introduced from Xalapa, Mexico, in 1838. 

 Among the early species to find their way into English gardens were the 

 Quamoclit, /. Quamoclit, and the popular Morning Glory, /. purpurea, 

 which were both introduced about 1629 from Tropical America. The 

 beautiful white-flowered 7. Bona-nox also came from Tropical America 

 nearly a hundred and fifty years later (1773), and I. pandurata irom 

 the United States in 1732. /. rwbro-ccerulea was brought from Southern 

 Mexico m 1830, 1. HorsfalUcB from the West Indies (1833), and 7. Learii 

 from Ceylon in 1839. All the species described below are twiners. 

 Several arborescent species have recently been introduced from Mexico. 

 Principaispecies Ipom^a Bona-nox (Good-night). Plant smooth. 



Stem chmbing to a height of 10 feet. Leaves heart- 

 shaped. Flowers white, 6 inches across, with very long tube ; July and 

 August. Stove annual. This is the " Moon-flower " of the Tropics. Its 

 flowers expand in the evening and wither in the early morning. 



L cocciNEA (scariet). Stem slender, 10 feet high. Leaves heart- 

 shaped, entire. Flowers bright scariet, small with long slender tubes; 

 July to October. Introduced from West Indies, 1713. The var 

 hederifolia, represented in Plate 196a, has the leaves deeply lobed. 



I. DiGiTATA (finger-leaved). A deciduous stove climber with a 

 thick tuberous rootstock and stout climbing stems bearing digitate 

 leaves and numerous panicles of rosy-mauve funnel-shaped flowers 3 

 inches across. Also known as 7 paniculata and Batatas panicidata. 



I HEDERACEA (Ivy-like). Stem 10 feet high. Leaves heart-shaped, 

 three-lobed. Flowers light blue, with hairy calyx ; July to September. 

 Half-hardy annual. The seeds yield the medicinal resin Pharbitisin. 



I. HoRSFALLi^ (Horsfall's). Leaves divided digitately into five 

 lance-shaped leaflets. Flowers in racemes, 2 inches across, rich crimson, 

 produced in winter. Stove evergreen, from the West Indies. A variety 

 of I. ternata, of which 7 thamsoniana, known as the White Horsfallife, 

 IS another variety with pure white flowers. 



I. PANDURATA (crooked). Stem 12 feet. Leaves heari:-shaped, 



