MONOCOTYLEDONS AND DICOTYLEDONS 275 



thyme (Thymus), balm (Melissa), sage (Salvia), catnip 

 (Nepeta), skullcap (Scutellaria), horehound (Marrubium), 

 lavender (Lavandula), rosemary (Rosmarinus), dead nettle 

 (Lamium) (Fig. 259), Teucrium (Figs. 213, 260), etc., a 

 remarkable series of aromatic forms. 



Allied is the Xightshade family (Solanacem), with fif- 

 teen hundred species, containing such common forms as 

 the nightshades and potato (Solanum), tomato (Lycoper- 

 sicum), tobacco (Xicotiana) (Fig. 208), etc., in which the 

 corolla is actinomorphic or nearly so ; also the great Fig- 

 wort family (Scrophulariacea?), with two thousand species, 

 represented by mullein ( Verbascum), snapdragon (Antir- 

 rhinum) (Fig. 210, e), toad-flax (Linaria) (Fig. 210, d), 

 Pentstemon, speedwell ( Veronica), Gerardia, painted cup 

 (Castilleia), etc.; also the Verbena family (Verbenacem), 

 with over seven hundred species ; and the two hundred 

 plantains (Plantaginacece), etc. 



147. Composites. — This greatest and ranking family 

 (Composite) of Angiosperms is estimated to contain at least 

 twelve thousand species, containing more than one seventh 

 of all known Dicotyledons and more than one tenth of all 

 Seed-plants. Xot only is it the greatest family, but it is 

 the youngest. Composites are distributed everywhere, but 

 are most numerous in temperate regions, and are mostly 

 herbs. 



The name of the family suggests the most conspicuous 

 feature — namely, the remarkably complete organization of 

 the numerous small flowers into a compact head which 

 resembles a single flower, formerly called a "compound 

 flower." Taking the head of an Arnica as a type (Fig. 

 261), the outermost set of organs consists of more or less 

 leaf -like bracts or scales (involucre), which resemble sepals ; 

 within these is a circle of flowers with conspicuous yellow 

 corollas (rays), which are zygomorphic, being split above 

 the tubular base and flattened into a strap-shaped body, 

 and much resembling petals (Fig. 261, A, D) ; within the 



