BINDWEED FAMILY 345 



Ord. LIIL Convolvulace^. — The Bindweed .F.vmily 



An extensive and highly valuable family of plants, most of 

 which are herbaceous climbers, with large and very beautiful 

 flowers. They are most abundant within the Tropics. They have 

 frequently a milky juice : their leaves are scattered and exstipulate; 

 their sepals 5, inferior, imbricate, often very unequal, persistent ; 

 their corolla monosym metric, hypogynous, plaited, gamopetalous, 

 5-toothed, deciduous; stamens 5, inserted on the base of the 

 corolla-tube ; ovary of 2 — 4 united carpels, few-seeded, surrounded 

 below by a fleshy, ring-shaped disk; style single, 2 — 4-forked; 

 fruit a I — 4-chambered capsule. As medicines they occupy an 

 important station. The roots of Convolvulus Scammonia, a Syrian 

 species, furnish scammony ; jalap is prepared from a similar 

 gum-resin which abounds in the roots of several species of 

 Exogonium, beautiful Mexican climbers, with large, trumpet-shaped 

 flowers ; and Batatas edulis is no less valuable as a food in tropical 

 countries, its roots, known as sweet potatoes, abounding in starch 

 and sugar, and being very nourishing. Cuscuta (Dodder) is a 

 parasitic genus with branched, climbing, thread-like stems, no 

 leaves, and globular heads of small, wax-like flowers. The seeds 

 germinate in the ground, and the young plants climb the stems 

 of adjoining plants, sending out root-like suckers into them and 

 then losing their connexion with the ground. One species found 

 in Britain grows upon Flax, with the seeds of which it has 

 probably been introduced ; and others grow on Furzes, Heaths, 

 Clovers and other plants. 



1. Convolvulus. — Leafy, twining plants. 



2. Cuscuta. — Leafless, twining parasites. 



I. Convolvulus (Bindweed). — Slender, twining plants, with 

 milky juice ; scattered leaves, often sagittate ; corolla trumpet- 

 shaped, 5-plaited, slightly 5-lobed; capsule 2-chambered below, 

 I -chambered above, 2-valved. (Name, a diminutive from the 

 Latin convolvo, I entwine.) 



I. C. sepium (Great Bindweed). — A glabrous, twining plant 

 with stout, fleshy, creeping rhizome ; leaves arrow-shaped, with 

 abrupt lobes ; bracts large, heart-shaped, close to the flower and 

 entirely enclosing it when in bud ; -flowers sohtary, on square 

 peduncles, large, pure white; jruit not often perfected. — Bushy 

 places ; common. A most mischievous weed in gardens, not only 

 exhausting the soil with its roots, but strangling with its twining 

 -^tems the plants which grow near. Its handsome flowers are 



