310 LXXV. COMPOSITiE. 



tivated for the use of the clothiers (fiillo?ium), wlio employ the heads with their 

 hard, hooked scales to raise the nap upon woollen cloths. For this purpose 

 they are fLsed around the circumference of a revolving drum. Flowers in July. ^ 



2. SCAB! OS A. 



Lat. scabies, leprosy ; plants said to be useful in cutaneous diseases. 



Flowers in heads ; involucre many-leaved ; involucel nearly cylin- 

 drical, with 8 little excavations ; calyx limb consisting of 5 setae, 

 sometimes partially abortive. — "A- Large^ mostly JEurojJean herbs with 

 opposite leaves. 



1. S. succisA. DcviVs-bit. — lit. premorse ; stem Ivs. remotely toothed ; hds. 

 ofjls. nearly globose ; cor. in 4 equal segments. — In gardens, though rarely cul- 

 dvated. The stem is about If high. Corolla violet, f 



2. S. ATROPURPLRKA. Moumuig Bride. — i/t-s. pinnatifid and incised ; hds. of 

 fls. radiant ; receptacle cylindric ; outer croion of the seed, short, lobed and crenate. — 

 A beautilul species, 2— -4f high, with dense heads of dark purple flowers. •}• 



Order LXXV. COMPOSITE.— Asterworts. 



clants herbaceous or shrubby. 



1,V3. alternate or opposite, without stipules, simple thoujjh often much divided. 



Fls. collected into a dense head (capitulumj, upon a common receptacle, surrounded by an involucre of 



many bracts (scales). 

 Cal. closely adherent to the ovary, the limo wanting, or membranaceous and divided into bristles, hairs, 



&c. , called pappus. 

 Cor. superior, consisting of 5 united petals, either ligidate or tubular. 

 Bta. 5, alternate with the lobes of the corolla, .int/i. cohering into a cylinder. 



Ova. interior, 1-celled, 1-ovuled. Style 2-cieft, the inner margnis of the branches occupied by the stigmas. 

 lY. an achenia, dry, indehiscent, 1-seeded, crowned with the pappus. 



This is the most extensive and most natural of all the orders of the vegetable kingdom, always distin- 

 guished at sight by the capitate flowers and the united anthers. It comprehends 1005 genera (at present 

 known, 1846), and about 90uo species ; being nearly one-ninth of all the species of flowering plants. The 

 general inflorescence is centritlrgal, that is, the central or terminal heads are first developed, while the 

 inflorescence of the heads is centripetal, the outer flowers first expanding. In color the flowers are vari- 

 ous ; sometimes those of the disk and ray are of difierent colors, again they are all of the same, but in the 

 former case the disk florets are idniost always yellow. 



This immense order is dillused throughout all countries of the globe, but in very difierent proportions. 

 According to Humboldtj they constitute about one-seventh of the Phaenogamous Flora of Germany, one- 

 eighth, of France, one-hfteenth, of Lapland, one-sixth, of North America (north ofMexico), and one-half, 

 of Tropical America. In New Holland they are in the proportion of about one-sixteenth, according to 

 Brown, while in the island of Sicily they are one-half The Liguliflora; are said to be most abundant in 

 cold regions, and the Tubuliflors in hot regions. The Labiatiflora; are almost exclusively confined to 

 .South America. In the northern parts of the world the Compositai are uni\'ersally herbaceous, but towards 

 the tropics they gradually become frutescent and even trees. In Chili they are generally shrubs, and on 

 the island of St Helena they are trees. 



Properties, ^c— The Compositit furnish comparatively few useful products. A bitter principle per- 

 vades the whole, which, when combined with resin and astringent mucilage, becomes tonic andfebrifu- 

 gal, as in the camomile, colt's-foot, thoroiighwort, goldenrod, &c. Some are ant/iehnintics from "the 

 prevalence ot the resinous principle, as taiisey, Artemisia, Vernonia. Others are aromatic and extremely 

 bitter, as wormwood and all the species of Artemisia. 0tl*r species are very acrid, as mayweed. The 

 Jerusalem artichoke (Helianthus tuberosus), the vegetable oj'ster (Tragopogon), the true artichoke 

 (Cynara), lettuce, dandelion and a few others, are the only species useful for food. The order abounds in 

 ornamental plants of the highest interest to the florist, and of easy culture. Among these are the splen- 

 did Dahlias and Chinese Chrj-santhema, with the numerous progeny of Aster, Helianthus, Xeranthemum, 

 Coreopsis and multitudes of others, constituting the richest ornaments of the autumnal Rower garden. 



The inflorescence of the ComposittE is peculiar, and its real nature often complex and obscure. The 

 following^definitionsxif terms are given with reference to this order only, and if understood, will remove 

 many ditficulties that lie in the student's way in the investigation of this subject. 



Copituluiii or )jead (compound Jlower of the earlier botanists) ; a collection of flowers (Jlorets) on a 

 common receptacle iracliis), as in Aster. Helianthus, &C- 



Involucre (calyx by analogy) is the lower and outer envelope of the head. 



Scales ," the modified leaves or bracts composing the involucre. 



Monophyllovs involucre ; where the scales are united by their edges. 



Polypliyllovs involucre ; where the scales are distinct. 



Simple involucre ; where the scales are equal and arranged in a single row. (short ones. 



Calyculate involucre ; where a single row of scales is surrounded at base by an outer row of veiy 



Imbricated involucre ; where the scales are in several rows, the outer ones becoming gradually shorter. 



The Receptacle or racliis is the dilated extremity of the peduncle, inclosed by the involucre, and upon 

 which the flowers stand. It is 



Columnar, flat, conical or depressed, according to its form ; 



Paleaceous or clwjf'y, where the flowers are subtended by chaffy scales which are analogous to bracts ; 



Alveolate, where it presents the appearance of a honey-comb, each flower having been surrounded by a 

 membranous rim or involucel ; 



Areolate, where the aheoli are reduced to a mere line ; 



Pimbrillate, where the alveoli are split into teeth or bristles ; 



Naiitd, when smoothith, being destitute of chafl, alveoli, bristles, &c. 



