RHINACANTHUS COMMUNIS 189 



lower lip ending in a spur. Ovary free, 2-celled, each cell 

 containing 2 ovules. Style filiform, long, inserted in a sort of 

 canal formed by the upper lip of the corolla. Stigma bilobu- 

 late. Seed vessel depressed, 4 flattened, lenticular seeds. 

 Habitat. — Luzon and Panay. 



Rhinacanthus communis, Nees. (Justicia nasuta, L.) 



Nom. Vulg. — Tagaktagak, Tag.; Nagamulli, Indo-Eng. 



Uses. — The plant has much reputation in India in the treat- 

 ment of skin diseases, and indeed its efficiency is great in the 

 stubborn Tinea circinata tropica, known throughout the Orient 

 as " dhobie-itch." In this disease it is applied for several days 

 to the affected part in the form of a paste composed of the 

 bruised leaves, the juice of the leaves and lemon juice. The 

 fresh root also may be employed. The Hindoo physicians 

 state that the root decoction in milk is aphrodisiac ; the root 

 is also regarded as an antidote for the bite of the " cobra da 

 cabelho," but its virtue is purely imaginary. Of late years 

 the plant has been used in Europe under the name of " tong- 

 pang-chong," to treat chronic eczema. 



Liborius made an analysis of the root in the laboratory of 

 Dorpat, separating 13.51J& ash and l.S7f> rhinocantkin, as well 

 as other ingredients. Rhinocanthin (C 14 H 18 4 ) is supposed to 

 be the active principle of the root. It is analogous to quinon 

 and resembles in many particulars chrysophanic and frangulic 

 acids. It forms a resinous, amorphous mass, cherry red, 

 odorless and tasteless, slightly soluble in water, forming a 

 mildly alkaline solution in alcohol. It does not yield glucose 

 when boiled with dilute hydrochloric acid. Liborius believes 

 that it exists only in the intercellular spaces of the " root bark." 



Botanical Description. — A shrub, about 4° high, stem 

 ash-colored, no spines. Leaves lanceolate, undulate, downy. 

 Flowers white in spikes. Calyx gamosepalous, 5-toothed. 

 Corolla long, filiform, limb 4-lobed, the 3 lower lobes ovate, 



