Widens.'] 



XLVI. COMPOSITES : CORYMBII^EE.^. 



237 



Tribe III. Corymbifer^. 



Heads either discoid; -vvlth the florets of eacli uniform and 

 usually tubular (Tab. IV. C), or those of the circumference 

 filiform or tubular and pistillate only : — or rai/ed (Tab. IV. D.) 

 when furnished with a ray consisting of ligulate pistillate or 

 neuter spreading florets. Style of the perfect florets not swollen 

 beneath its branches.^ (Gen. 24 — 46.) 



Subtrlbe I. Tubiflor^. Heads discoid.^ (Tab, IV. C.) 



[(Gen. 24—33.) 



Pappus of awns or wanting, (Gen. 24 — 27.) 



24. BiDENS Linn. Bur-marigold. 



Pappus of 2 — 5 persistent awns, which are. rough with minute 

 deflexed prickles, lieceptacle chaffy. Involucre of many scales ; 



1 This tribe is an extensive one, and at first sight will appear less natural and 

 less recognizable by the inexperienced 63^6, than the two former tribes. The 

 greater number of the genera and species wliich compose it, have radiate tlowers, 

 and then they are readily distinguished. Of this we have very famih'ar examples 

 in the Daisy (Tab. IV. D.), the Ox-eye and the Leopard' s-hane ; but in many 

 cf'ses the ray is so small as to be hardly perceptible, as in the Cud-iveeds ; or it is 

 wholly wanting, as in the Ileynp- agrimony. Bur marigold, and in the IJiotis or 

 Coiton-tveed (Tab. IV. D.)- Ii^ thes^e latter then the florets are all tubular ; but the 

 student will observe that the florets do not spread, as in most of the Thistle tribe, 

 that the corolla is not remarkably Inflated b:'low the month, nor is the style swollen 

 below the branches ; and he would never think of arranging any one of them with 

 the Thistles. A reference to our figures and a comparison of them with the figures 

 of the two preceding tribes, will show at once the essential distinctions. 



Tab. IV. C. Fig. 1. Head of flowers of 7Jzb^/5 ; the florets all tubular, erect, 

 crowded, parallel (not spreading), surrouiulod by the scaly and woolly involucre. 



Fig. 2, Single fluret taken from the recej>tacle, with its chaffy scale'. Within the 

 fringed scale is seen, at the base of the floret, the germen (destitute of pappus), 

 upon which is the tubular corolla, with its two curious ears at the base, and in- 

 cluding the stamens and pistil. 



Fig. 3. Upper part of the style, showing no swelling. 



Figs. 4. 5. Fruits, with the withered and persistent base of the corollas. 



All more or less magnified. 



Tab. IV. D. Fig, 1. Head of flowers of the Common Daisy (Bellis perennis)^ 

 showing the tubular florets in the centre, and the ligulate ones forming a ray in 

 the circumference, all within the involucre. 



Fig. 2. Involucre, with the conical receptacle ; all the florets being removed. 



Fig. 3. F^loret of the ray or circumference, having at its base the germen desti- 

 tute of pappus, and above it the ligulate or strap-shaped corolla, exhibiting in its 

 short cylindrical base only a style and no stamens : it is, therefore, imperfect, but 

 fertile, the pistil being fertilized by the anthers of the central florets. 



Fig. 4. Floret of the centre or disk, having, at the base, the germen, destitute of 



pappus ; above that, the tubular corolla, including the stamens and style : it is, 

 therefore, perfect. 



All more or less magnified. 



The name Corymb?ferce was given to this tribe or division of CompositcB, be- 

 cause, m many cases, as hi the Hemp-Agrimony^ Tansy, Sec, the he;^ds of flowers 

 are arranged m corymbs; but this is bvno means universally the case. 



In iJidens there is occasionally a true ray. In Tanacetum somewhat tubular 

 florets with a short ligule, and in Ariemisia, Gnnphalium, and Petasites, slender 

 ones with a fihform inconspicuous erect ligule are sometimes observed in the cir- 

 cumlerence, but m these cases the heads can scarcely be said to be raye*d. On the 

 otner hand some species of Senecio, in the second subtribe, are without a ray, and 



^/l^hf^^r^^l , ^?7^^?-on and Inula have it erect and so inconspicuous that they 

 might almost be looked for in the present subtribe 



