Lavender (lavandula Vera D C; L Spica D C)

These plants, which are mostly natives of mild climates of the old

world, are characterized by having square stems; opposite, simple leaves

and branches; and more or less two-lipped flowers which appear in the

axils of the leaves, occasionally alone, but usually several together,

forming little whorls, which often compose loose or compact spikes or

racemes. Each fertile blossom is followed by four little seedlike fruits

in the bottom of the calyx, which remains attached to the plant. The

foliage is generally plentifully dotted with minute glands that contain

a volatile oil, upon which depends the aroma and piquancy peculiar to

the individual species.

The leading species of the Umbelliferae are: