268 ROBINSON. 



included even those of wide distribution and in some cases of weedy 

 character) somewhat exceeds the element common to Ecuador (19 

 species). On the other hand the actual affinities of the Colombian 

 Eupatoriums, when determined by the more characteristic and more 

 certainly native species of limited range, are more strongly Ecuadorian 

 than Venezuelan. 



There seems no reason to suppose that the statistical relations here 

 presented on the basis of this large and di\'ersified genus will not be 

 found to hold their approximate ratio in many other groups. Un- 

 fortunatel.>- the present state of knowledge regarding the details of 

 plant-distribution in Colombia, as well as of the geological, meteoro- 

 logical, and physiographic conditions, is still much too slight to permit 

 generalization regarding ecological relations or soil-influence in de- 

 termining the present flora. 



EUPATORIUM [Tourn.] L. Heads homogamous, (1-4)5- ^-flow- 

 ered. Involucre cylindrical to campanulate; the scales of indefinite 

 number, usually numerous, commonly graduated and appearing to be 

 arranged in 2-8 series, the inner progressi^'ely longer, more rarely almost 

 all subequal and with only a few (1-3) of the outermost considerably 

 shorter. Receptacle flat or in varying degree convex to conical, 

 glabrous or in one section pubescent, calvous. Corolla tubular, with 

 or without a perceptibly enlarged campanulate, turbinate, or cylindri- 

 cal throat; the limb (4-)5-toothed, regular. Anthers mostly connate 

 but sometimes nearly or quite free, rounded (to rarely and obscurely 

 cordate or subsagittate) at the base, provided at the summit with an 

 ovate or oblong mostly obtuse rarely retuse membranaceous append- 

 age. Style-branches much exserted, the appendage elongate, filiform 

 or more commonly somewhat clavate, smooth or microscopically 

 papillose. Achenes 5-angled, the angles usually rib-thickened and of 

 modified texture, color, or pubescence, the intervals flat or often 

 concave, occasionally provided with lesser ribs intermediate between 

 the main ones. Pappus of 10- cc bristles, for the most part nearly or 

 quite equalling the corolla; the bristles truly capillary or slightly 

 firmer, white or sordid, sometimes tinged with rose or purple, rarely 

 tawny, usually (at least when examined with a compoimd micro- 

 scope) hispidulous, never strongly plumose. — Sp. PI. ii. 836 (1753); 

 L. f. Suppl. 354 (1781); HBK. Nov. Gen. et Spec. iv. 105-134 (1820), 

 excl. certain species; DC. Prod. v. 141-186 (1836); Benth. & Hook, 

 f. Gen. ii. 245 (1873); Pak. in Mart. Fl. Bras. vi. pt. 2, 274-365, t. 

 76-96 (1876); Klatt in Engl. Bot. Jahrb. viii. 33-36 (1887); Holfm. 

 in Engl. & Prantl, Nat. Pflanzenf. iv. Abt. 5, 138 (1890); Hieron. 



