=Serrulate.= Finely or minutely serrate. =Sessile.= Without a stalk, petiole, or pedicel. =Sheathing.= Inclosing. =Simple.= In one piece; not compound; usually applied to leaves with a single blade. =Sinuate.= Wavy-margined. =Sinus.= The angle between two lobes or divisions. =Spadix.= A short fleshy spike. =Spathe.= A large bract or pair of bracts enclosing a flower-cluster. =Spatulate.= Shaped like a spatula, with a narrow base and an enlarged, more or less rounded summit. =Spike.= An elongated flower-cluster having sessile flowers upon an unbranched axis. =Spike-like.= Resembling a spike. =Spinulose-serrate.= Provided with teeth tipped with minute spines. =Spur.= A hollow projection from the calyx or corolla, usually slender in shape, and generally directed backward. =Stamen.= One of the organs of a flower, consisting of a filament and anther. =Staminate.= Bearing stamens. =Stolon.= A short stem arising from the base of a plant, prostrate or nearly so, and eventually taking root. =Striate.= Marked with fine stripes or ridges. =Style.= A portion of the pistil, usually slender, and connecting the ovary and stigma. =Superior.= A superior ovary occupies the center of the flower and is not attached to any other floral organs. =Subtending.= Situated at the base of an organ. =Subulate.= Awl-shape. =Ternately.= Divided by threes. =Tomentose.= Densely hairy with matted or tangled hairs. =Trifoliate.= With three leaflets. =Truncate.= Cut straight across at the tip, or nearly so. =Tube.= The more or less cylindrical portion of a gamosepalous calyx or a gamopetalous corolla, distinguished from the expanded or lobed terminal portion. =Tubular.= Shaped like a tube. =Twice-pinnate.= Same as bipinnate. =Two-lipped.= A calyx or corolla in which the upper half is decidedly different in size or shape from the lower. =Umbel.= A flower-cluster with several or many pedicelled flowers all arising from the same point. =Undulate.= With a wavy margin. =Viscid.= Sticky. =Villous.= With long soft hairs. =Whorl.= An arrangement of 3 or more leaves or flowers in a circle around a node. =Whorled.= In a whorl. =Wing.= A thin flat expansion on the sides or edge of an organ. INDEX Abies, 1 Abutilon, 72 Acalypha, 66 Acanthaceae, 107 Acanthus Family, 107 Acer, 70 Aceraceae, 70 Acerates, 90 Achillea, 130, 131 Acnida, 30 Acorus, 8 Actaea, 39 Actinomeris, 128 Adder's Mouth, 17 Adenocaulon, 118 Adlumia, 41 Aesculus, 70 Agastache, 97 Agrimonia, 55 Agrimony, 55 Agropyron, 6 Agrostemma, 33 Agrostis, 6 Ailanthus, 65 Aizoaceae, 31 Alder, 22 Alder, Black, 69 Aletris, 13 Alfalfa, 61 Alisma, 3 Alismaceae, 3 Allium, 13 Alnus, 22 Alopecurus, 4 Alsike Clover, 61 Althaea, 72 Alum Root, 50, 51 Alyssum, 42, 46 Alyssum, Yellow, 42, 46 Amaranth Family, 30 Amaranthaceae, 30 Amaranthus, 30 Amaryllidaceae, 14 Amaryllis Family, 14 Ambrosia, 114