180 COMPOSITE FAMILY. 



* * Pappus of naked, rough or short-barbed bristles, or none. 

 t- Filaments of the stamens united into a tnhe. Leaves white-variegated. 



3. SILVni'.M. Scales of the involucre with the upper p:irt leaf-like and -pread- 



ing, -piny. I.Veeptaele I t with bri-ti.--. Akencs flattened: pappus of 



many rather short and rigid bristle- minutely bearded on their edges. 



<-(- Filaments separate. 



4. ONOPORDON. Heads and flowers as in true Thistles, No. 2. Receptacle naked 



and honeycombed. Akenes 4-augled, wrinkled: pappus of many slender 

 hri-tle, united at base into a horny ring. Stem- -trough- leaf-winged. 

 6. LAPP A. Scales of the globular involnnv abruptly tipped with a spreading 

 slender a\vl-.-baped appendage, mostly hooked at it- point. Receptacle bristly. 

 Akenes llattened, wrinkled: pappus of many short and rough bristles, their 

 ba-e- nut united, decidunus. Leaves and -talks not prickly. 



6. CAKTIIAMl'S. Outer scales of the involucre leaf-4ike and spreading, middle 



ones with ovate appeudaire fringed with spiny teeth or little spines, innermost 

 entire and sharp-pointed. Receptacle beset with linear chaff. Akenes very 

 smooth, 4-ribbed: pappus none. Loaves with rigid or short spiny teeth. 



7. CN 7 ICUS and 8. CENTAUREA; see next division. 



2. Thistle-like or Scabious-like, with many-ranked imbricated scales to the involucre, 

 mmn/-tli>irers. and the tn;> branches of the style united into nn body almost or 

 quite to the tip, at in 1: but the outer floioers of the head different from the 



rest and sterile, except in a few species of Centaurea. Receptacle beset with 



bristles. 



1. CNICI'S. Outer flowers smaller than the rest, slender-tubular, sterile. ^Scales 

 of the involucre tipped with a long spine-like appendage which is spiny-fringed 

 down the sides. Akenes short-cylindrical, many-ribbed and grooved. Crtro ned 

 with 10 .-hort and homy teeth, within which is a pappus of 10 long and rigid 

 and 10 short naked bristles. Leaves prickly-toothed. 



8. CKNTAUREA. Outer flowers sterile and with corolla larger than the rest, 



often funnel-shaped and with long sometimes irregular lobes, forming a kind 

 of false ray; but these are wanting in a few species. Involucre various, but 

 the scales commonly with fringed, sometime- with spiny tips. Akenes flat or 

 rlattish: pappus of -evrral or many bristles or narrow scales, or none. 



3. Bur-like or achenium-like in the fruit, irhich is a completely closed involucre 

 confainiiitj onli/ one Or two flowers, consistiiii/ <>f n pistil only, with barely a, 

 rudiim at' of corolla, therefore very dijl't r< nt from must jitnnts of the family ; 

 but the staminate jftotoers are seven*/ mid i'u a ft/it or top-shaped involucre. 

 Heads Ihfri'/'ore moncecious, or rarely duecious: no pappus. Coarse and 

 homely weeds. 



y. XANTHIUM. Heads of staminate flowers in short racemes or spikes, their 

 involucre of several scales in one row: fertile flowers below them, clustered 

 in the axils, two together in a 2-celled booked-prickly bur. 



10. AMBROSIA. Heads of staminate (lowers in raceme- or spikes terminating the 



stem or branches, their involucre of several scales united in tlattish or top- 

 shaped cup; fertile (lowers clu-tered below the staminate, only one enclosed 

 in each small achenium-like involucre, which is naked, or with a few tubercles 

 or strong point- near the top in a i-ingle row. 



4 Plants not thistle-like nor bur-like. 

 * Two kinds ofjlowers in the same head, ll/e, outer ones u-ith pistils only. 



- Pappus none or a minute //order or cn]> : no i-lmj}' anioiiij the Jloiws : scales of the 

 iiii-oliirre. dry, uf/m irith sfarinug mnrt/ins, hiilirii-ntcd. Hitter-aromatic or 

 rather acrid plants. 



11. TAXACE'lTM. Heads ,,f many yellow flowers; the marginal ones with pistil 



only and a :! - ".-tootbed corolla.' Akene- an-l.-d or ribbed, with a Hat top, 

 crowned with a cup-like toothed or lobed pappus. Very strong-scented 

 herbs, with heads in a corymb. 



12. ARTEMISIA. Heads small, of few or many yellow or dull purplish flowers, 



some of the marginal ones pi.-tillate and fertile, the others perfect, but some- 

 times not maturing the ovary. Akenes obovate or club-shaped, small at the 

 top, destitute of pappus. Bitter-aromatic, and strong-scented plants, with 

 beads iu panicles. 



