LXV. COMPOSITE. 869 



_ 68. CENTIPEDA, Lour. 



(Referring to its creeping habit.) 



(Myriogyne, Less.; Sphseroraorphsea, DC. partly.) 



Involucral bracts in about 2 rows, nearly equal, scarious at the edges. Re- 

 ceptacle flat or slightly convex, without scales. Florets of the circumference 

 in many rows, female, with short tubular corollas ; disk-florets hermaphrodite, 

 fertile, broadly campanulate, 4-lobed. Anthers short, obtuse at the base. 

 Style-lobes very short, obtuse or truncate. Achenes not at all or scarcely com- 

 pressed, with 3 or 4 very prominent obtuse ribs or angles, without any pappus. 

 — Herbs with alternate usually toothed leaves. Flower-heads small, sessile, 

 lateral or in a short terminal raceme. 



A small genus, chiefly S. Asiatic, with one species from extratropioal S. America. Of the i 

 Australian species, 1 is the common Indian one, the others are endemic. 



Stems prostrate, diffuse. Flower-heads sessile or nearly so. Florets 



exserted. Achenes slightly hairy, ellipsoid-clavate 1. G. orbicularis. 



Stems erect or ascending. 

 Flower-heads sessile. Achenes not striate at the apex, oylindric-clavate 2. C. Cunninghami. 

 Flower-heais nearly semiovale. Achenes cylindrical, the pilose lines 



almost forming a pappus . . . . • 3. C. thespidioides. 



Flower-heads in short terminal racemes. Achenes 4 or 5-angled, angles 



ciliate i. G. racemosa. 



1. C. orbicularis (heads orbicular), Lour. Fl. Coch. A prostrate branching 

 annual or perhaps sometimes a perennial of short duration, the slender stems 

 2 to 3 or rarely 6in. long in tropical regions, glabrous or clothed with short 

 white woolly intricate hairs, in most of the extratropioal Australian specimens 

 more robust, glabrous, attaining sometimes 1ft. Leaves oblong, |- to |^in. long, 

 narrowed at the, base or almost petiolate, toothed or almost pinnatifid. Flower- 

 heads IJ to 2 lines diameter, solitary, at first terminal, but soon becoming 

 leaf-opposed, closely sessile or rarely accompanied by a second pedunculate one 

 (i.e. by a short 1-headed flowering-branch with the floral leaf abortive). Florets 

 very minute, the female corollas scarcely above a third of the length of their 

 ovaries. Styles of the disk-florets with very short truncate lobes. Achenes 

 slightly hairy. — Myriogyne minuta. Less.; Benth. Fl. Austr. iii. 553. 



Of this variable plant, 3 more or less distinct forms are met with in Queensland, viz.: — 



Var. minuta. A weak, prostrate, nearly glabrous plant, spreading from a few inches to over 

 a foot wide. Leaves oblong, about Jin. long, the lower ones on longish petioles, the upper end 

 with a few distant teeth ; with a slight pungent scent when bruised. — Myriogyne minuta. 

 Less. Hab.: Common on the southern coastal lands. 



Var. ste7-nutatoria. Branches somewhat erect from a procumbent base, stiff, clothed by short 

 rigid hairs. Leaves rather pungently toothed ; very pungently scented. — Artemisia sternutatoria , 

 Boxb. Hab.: Stanthorpe and many other inland localities. 



Var. lanuginosa. Whole plant densely woolly-white. — Myriogyne minuta, var. lanuginosa. 

 Hab.: Generally found in inland tropicul parts. 



These plants have been supposed to poison stock. Dried and powdered they form a good 

 snuff, and have the reputation of possessing ihedicinal virtues. 



2. C. Cunninghami (after Allan Cunningham), F. v. M. Fragm. viii. 

 An erect rigid herb here and there procumbent. Leaves ouneate-oblong w'ith 

 distant marginal teeth. Flower-heads sessile, bracts with scarious margins. 

 Florets very numerous, the females in many rows. Achenes cylindric-clavate, 

 not streaked at the summit. 



Hab,: Mount Perry, Jas, Keys, 



