LXV. COMPOSITE. 789 



2. CENTRATHERUM, Cass. 



Involucre imbricate, a few of the outer bracts long and leaf-like, the others not 

 longer than the florets, the inner ones the longest. Eeceptacle naked. Florets 

 all tubular and equal, regular, with 5 narrow lobes. Anthers obtuse at the base ; 

 style-lobes subulate. Achenes oblong, nearly cylindrical, striate. Pappus of a 

 single series of rigid, flattened, hirsute, very deciduous, almost chaff-like bristles. 

 — Herbs or shrubs. Leaves alternate. Flower-heads on terminal or leaf-opposed 

 peduncles. Involucres hemispherical. Florets usually purple. 



A small American genus, of wliioli two species, including the Australian one, have spread 

 over several of the warmer regions of the Old World. 



1. C. muticuin (pointless), Less.; DC. Prod. v. 70 ; Benth. Fl. Austr. 

 iii. 460. A rigid divaricately branched herb, probably annual although 

 with a hard almost woody base, spreading to 2 or 3ft., glabrous or pubescent. 

 Leaves petiolate, lanceolate-oblong or almost ovate, 1 to 2in. long, coarsely and 

 irregularly toothed. Flower-heads often above ^in. diameter, the outer leafy 

 bracts \ to lin. long, the inner ones numerous, with spreading more or less 

 coloured or scarious denticulate tips. Florets purple, much longer than the 

 involucre. Achenes usually glabrous, with about 10 very obtuse ribs, the pappus 

 falling off even before they are ripe. 



Hab : Brisbane Eiver, Moreton Bay, F. u. Mueller ; Bookhampton, Dallachy. 

 The species is common in tropical America ; we have also apparently the same from the 

 Philippine Islands. — Benth. 



3. PLEUROCARP.ffiA, Benth. 



(Achenes ribbed.) 



Involucre ovoid, the bracts few, herbaceous, imbricate, not so long as the 

 florets. Eeceptacle without scales. Florets all tubular and equal, regular, often 

 incurved, with 5 narrow lobes. Anthers sagittate at the base, the auricles pro- 

 duced into short not fine points. Achenes thick, with prominent ribs. Pappus 

 of 2 to 5 rigid short exceedingly deciduous bristles. — Leaves alternate, entire or 

 toothed. Flower-heads on terminal peduncles. 



The genus is limited to a single species endemic in Australia, not nearly allied to any one 

 known to me, unless it be to some anomalous species of Decaneuriim. — Benth. 



1. P. denticulata (leaves toothed), Benth. Fl. Austr. iii. 460. Herbaceous, 

 with hard divaricate or decumbent branches, our specimens above 1ft. long and 

 quite glabrous. Leaves ovate or oval-elliptical, mucronate-acute, contracted into 

 a very short petiole, the larger ones above 2in. long, irregularly bordered by acute 

 teeth, the upper ones smaller and entire. Peduncles terminal, solitary or 2 

 together, 1 to 2in. long or longer after flowering, slightly thickened under the 

 head. Involucre about 4 lines long, thickened at the base, the bracts broadly 

 lanceolate, acuminate. Florets about 10 to 20, of a bluish purple, the tube 

 exceeding the involucre, often incurved, shortly dilated into a deeply 5-lobedlimb. 



Hab.: Islands of the Gulf of Carpentaria, R. Brown, who had given it the provisional name of 

 Lipothrix denticulata, but he afterwards published as Lipotriche, a very different African 

 plant. — Benth. 



4. VERNONIA, Schreb. 



(After Wm. Vernon.) 



Involucre ovoid-globular or hemispherical, the bracts imbricate, not longer than 

 the florets, the inner bracts the longest, Eeceptacle without scales. Florets all 

 tubular and equal, regular, with 5 narrow lobes. Anthers obtuse at the base. 

 Style-lobes subulate. Achenes mostly striate or angular, rarely cylindrical. 



