SCORPIOIDAL, like the tail of a scorpion; a peculiar twisted cymose inflorescence, as in _Boraginaceæ_. SCURFY, applied to stems and leaves covered with loose scales. SECUND, turned to one side. SECUNDINE, the second coat of the ovule, within the primine. SEGMENTS, divisions. SEGREGATE, separated from each other. SEMINAL, applied to the cotyledons, or seed-leaves. SEPAL, one of the leaflets forming the calyx. SEPTATE, divided by septa or partitions. SEPTICIDAL, dehiscence of a seed-vessel through the septa or edges of the carpels. SEPTIFRAGAL, dehiscence of a seed-vessel through the back of the loculaments, the valves also separating from the septa. SEPTUM, a division in an ovary formed by the sides of the carpels. SERICEOUS, silky; covered with fine, close-pressed hairs. SERRATE, having sharp processes arranged like the teeth of a saw; _Biserrate_, when these are alternately large and small, or where the teeth are themselves serrated. SERRULATE, with very fine serratures. SESSILE, without a stalk, as a leaf without a petiole. SETA, a bristle or sharp hair; also applied to the gland-tipped hairs of _Rosaceæ_ and _Hieracium_, and to the stalk bearing the theca of mosses. SETACEOUS and SETIFORM, in the form of bristles. SETIFORM, bristle-shaped. SETOSE, covered with setæ and bristles. SHEATH, the lower part of the leaf surrounding the stem. SILICULA, a short pod with a double placenta and replum, as in some _Cruciferæ_. SILIQUA, a long pod, similar in construction to the silicle. SIMPLE, not branching, not divided into separate parts. Simple fruits are those formed by one flower. SINUOUS, with a wavy or flexuous margin. SINUS, the base or recesses formed by the lobes of leaves. SLASHED, divided by deep and very acute incisions. SOCIAL PLANTS, such as grow naturally in groups or masses. SOREDIA, powdery cells on the surface of the thallus of some lichens. SPADIX, a succulent spike bearing male and female flowers, as in _Arum_. SPATHE, large membraneous bract covering numerous flowers. SPAWN, same as Mycelium. SPECIFIC CHARACTER, the essential character of a species. SPERMAGONE, a microscopic conceptacle in lichens, containing reproductive bodies called spermatia; also a conceptacle containing fructification in fungi. SPERMATIA, motionless spermatozoids in the spermagones of lichens and fungi. SPERMODERM, the general covering of the seed, sometimes applied to the episperm or outer covering. SPHEROIDAL, nearly spherical. SPIKE, inflorescence consisting of numerous flowers sessile on an axis. SPINE, or THORN, an abortive branch with a hard, sharp point. SPIRAL VESSELS, having a spiral fibre coiled up inside a tube. SPONGIOLE, the cellular extremity of a young root. SPORANGIUM, a case containing spores. SPORE, a cellular germinating body in cryptogamic plants.