444 EXOGENOUS OR DICOTYLEDONOUS PLANTS. 



on the roots of other plants ; the flowers solitary or spicate. Calyx 

 persistent, four- or five-toothed or bilabiate. Corolla withering or 

 persistent, with a bilabiate or more or less irregular limb. Sta- 

 mens four, didynamous, inserted on the corolla. Ovary free, one- 

 celled, with two parietal placentae ! which are often two-lobed, or 

 divided. Capsule inclosed in the persistent corolla. Seeds very 

 numerous, minute. Embryo minute at the extremity of the albu- 

 men. Ex. Orobanche, Epiphegus (Beech-drops), &c. Astrin- 

 gent, bitter, and escharotic. The pulverized root of Epiphegus 

 (thence called Cancer-root) is applied to open Cancers.* 



834. Ord, BiglloniaceSB (the Bignonia Family}. Mostly trees, or 

 climbing or twining shrubby plants, with large and showy flowers, 

 and opposite, simple, or mostly pinnately-compound leaves. Ca- 

 lyx five-parted, two-parted, or bilabiate, often spathaceous. Corol- 

 la with an ample throat, and a more or less irregular five-lobed or 

 bilabiate limb. Stamens five, inserted on the corolla, of which 

 one, and often three, are reduced to sterile filaments or rudiments : 

 when four are fertile, they are didynamous. Ovary two-celled, 

 with the placentae in the axis ; the base surrounded by a fleshy 

 ring or disk. Capsule woody or coriaceous, pod-shaped, two- 

 valved, many-seeded. Seeds winged, destitute of albumen. Co- 

 tyledons foliaceous, flat, heart-shaped, also notched at the apex. 

 Ex. Bignonia (Trumpet-Creeper), Catalpa, and other tropical 

 genera. Of little importance, except as ornamental plaijts. 



835. Subord, Sesameae (the Sesamum Family) has few and wingless 

 seeds ; the fruit indurated or drupaceous, often two- to four-horned, 

 sometimes perforated in the centre from the dissepiments not 

 reaching the axis before they diverge and become placentiferous, 

 and spuriously four- to eight-celled by the various cohesion of 

 parts of the placentae with the walls of the pericarp. Ex. Sesa- 

 mum, Martynia (Unicorn-plant), and some other tropical plants. 



836. Ord, Acanthaceffi (the Acanthus Family). Herbs or shrubby 

 plants, with bracteate, often showy flowers, and opposite, simple 

 leaves, without stipules. Calyx of five sepals united at the base, 

 or combined into a tube, persistent. Corolla bilabiate, or some- 



* ORD. GESNERIACEJE, consisting of tropical herbs, with green foliage 

 and showy flowers, the calyx often partly adherent to the ovary, agrees with 

 Orobanchacese in the parietal placentalion, by which both are distinguished 

 from all other orders of this group. 



