Wollcustonia.'] composite. 183 



1. W. biflora, DC. Prod. v. 546; Wight, Ic. t. 1108. A straggling 

 half-scandent branching perennial, sometimes nearly glabrous, but more fre- 

 quently slightly hoary with closely appressed rigid hairs, especially on the 

 under side of the leaves. < Leaves stalked, from broadly ovate to ovate-lanceo- 

 late, the lowest sometimes 3 to 4 inches long and very broadly cordate, the 

 others usually smaller and often cuneate at the base, all acute or acuminate, 

 slightly toothed, 3-nerved. Flower-heads 2, 3, or more, in loose terminal 

 corymbs. Eay -florets about 10 or 12, not so broad as in the Weddia. — 

 W. scabriuscula, DC. I.e. 547; W. strigulosa, DC. I.e. 548; and probably 

 some others among the described Wollastonias. Verbesina scandens, Eoxb. 

 Fl. Ind. iii. 441. 



About rocks and hedges close to the seaside, Champion ; also Wright. Widely spread over 

 India, extending westward to E. tropical Africa, eastward over the Archipelago to N. Aus- 

 tralia, and northward to S. China and Loochoo. 



24. BIDENS, Linn. 



Flower-heads usually heterogamous. Florets of the ray neuter, ligulate, 

 or sometimes wanting. Disk-florets hermaphrodite, 5 -toothed. Involucral 

 bracts few, in about 2 or 3 rows, the inner usually bordered with a thin whitish 

 margin. Eeceptacle chaffy. Style-branches in the disk-florets with an acute 

 or subulate point. Achenes slender and 4-angled, or (in some species not in 

 Hongkong) broader and flattened, often shortly beaked. Pappus of 2 to 4 

 rigid retrorsely hispid persistent awns. — Leaves opposite. 



The genus comprises 2 sections. The one, Platycarpcea, with flattened achenes, belongs 

 chiefly to the temperate regions of the northern hemisphere, the other, Psilocarpcea, is en- 

 tirely American, with the exception of the two subjoined species, which are spread over all 

 warm countries. 



Leaves mostly pinnate, with 3 or 5 segments. Ray white 1. B. pilosa. 



Leaves mostly bipinnate. Ray yellow 2. B. bipinnata. 



1. B. pilosa, Linn. ; DC. Prod. v. 597. An erect glabrous or slightly 

 hairy annual, 1 to 2 ft. high. Branches angular. Leaves thin, pinnately 

 divided, or the lower ones sometimes simple : segments 3 or sometimes 5, 

 stalked, ovate or ovate-lanceolate, 1 to 2 in. long, serrated or rarely lobed. 

 Flower-heads few, terminal, rather small, on slender peduncles. Involucral 

 bracts 2 to 3 lines long. Ray-flowers white, few and short, or sometimes 

 wholly wanting. Achenes slender, 4-angled, the central one often 6 or 7 lines 

 long, the outer ones shorter. — B. leucantha, Willd. ; B. sundaica, Bl. ; and 

 B. Wallichii, DC. I.e. 598. 



A common weed of cultivation in the island, as over most warm countries both in the New 

 and the Old World. It varies much in the relative numbers of the bordered and unbordered 

 involucral bracts, in the length of the inner achenes, and in the number and size of the ray- 

 flowers when present. The Chinese specimens are generally radiate, with the inner bracts 

 conspicuously bordered, the outer unbordered ones few, small, and narrow. 



2. B. bipinnata, Linn.; DC. Prod. v. 603. A glabrous annual, re- 

 sembling the last, but the leaf-segments are usually again divided into small 

 deeply toothed or lobed segments, the flower-heads are smaller, the involucral 

 bracts less bordered, and the ray-florets small and yellow. 



A weed of cultivation like the last, and more common in some countries, but apparently 

 less so in Hongkong, where it has only been gathered by Champion. 



