260 DESCRIPTIVE BOTANY. 



due to the resemblance of the pod to the sheath of a knife. Aromatica, the 

 specific name, signifies " spicy." Planifolia means " flat-leaved." 



History. — Vanilla is the only orchid whose product is of commercial impor- 

 tance. It is a native chiefly of tropical America, and was brought to the 

 notice of Europeans by the Spaniards, who found it in use among the Aztecs 

 when they invaded Mexico. 



Chemistry. — The flavoring substance of vanilla is called by chemists vanil- 

 lin. It has been produced artificially in the laboratory. 



Preparation. — The best vanilla is the product of the V. planifolia. The 

 beans are removed from the vine as soon as they have attained their full size, 

 but before they are ripe, and are placed in a situation that exposes them to 

 the heat of the sun or to artificial heat, — a part of the time wrapped in cloths, 

 and a part of the time exposed. Under this treatment they attain their aroma 

 and dark color, and are made fit for the market. The pods are fleshy, flexible, 

 compressed or cylindrical, five to ten inches long, dark-brown, slender, hooked 

 at the stalk end, the surface furrowed lengthwise, with a greasy, shining 

 appearance when properly cured. After a few months the surface becomes 

 covered with a bloom of fine crystals of vanillin. The pods are prepared for 

 market by sorting into lengths and qualities, tying up iu parcels of fifty 

 each, and packing the bundles in tin boxes that hold twenty to fifty pounds 

 each, which are then incased in cedar boxes, holding four to six tins. 



Use. — Vanilla was formerly used as a medicine for stomach disorders and 

 indigestion. Its use at present is for flavoring. It is added to chocolate, ice- 

 cream, sauces, syrups for soda-Avater, tobacco, snuffs, liquors, and perfumery. 



Order LV. ZINGIBERACE^. 



Flowers irregular, in a raceme, or a terminal or lateral bracteate 

 panicle. Perianth superior, formed of 3 to 4 whorls. Calyx green, 

 3-Ieaved, imbricate. Corolla of 3 imbricated divisions, alternating 

 with the divisions of the calyx, colored and tubular at the base ; sta- 

 mens 1-6. Ovary inferior, 1-3-celled ; style sometimes dilated, 

 petal-iike, straight or curved, sometimes slender. Stigma terminal; 

 capsule 1-3-celled. Seeds globular or angular ; testa leathery. Leaves 

 alternate, simple ; petioles sheathing ; blade plane large, entire, veins 

 extending from the midrib. Herbs, frequently gigantic. 



No. of genera, 36 ; species, 450 ; in warm climates. 



CURCUMA, L. Calyx tubular, 3-toothed. Corolla tube dilated 

 upwards; divisions of the limb equal; upper lip open. Filament 

 petal-like, dilated, fleshy at the top ; lateral staminodia united with it 

 below, 3-lobed. Ovary inferior, 3-celled. Style thread-like ; stigma 

 capitate. Capsule 3-celled ; cells 3-valved. Seeds numerous, arillate. 

 Root tuberous and palmate, perennial. Leaves herbaceous ; petioles 

 sheathing; scope simple. Flowers in a simple, erect spike, yellow. 

 Stemless herb. 



C. long-a, L. (Turmeric.) Stem wanting. Leaves sheathing each other, 

 lanceolate, a foot long, springing from the crown of the root ; the scape passes 



