Tetragonotheca. COMPOSIT.E. 255 



Torr. &, Gray, 1. c, excl. vars. ; Meehan, Nat. Flowers, ser. 2, ii. 42. Bupldhalmum heli- 

 anthoidcs, L. Hort. Ups., & Spec. ii. 904; Michx. ¥\. ii. 130; L'Her. Stirp. t. 45. Silphium 

 helianthoides, L. Spec. ii. 920, pi. Grouov. 5. soUdcujinoidcs, L. Spec. 1. c. Rudbeckia oppositi- 

 folia, L. Spec. 1. c. 907, pi. Grouov. Heliantluis Icevis, L. Sjiec. ed. 2, 1278, excl. syn. Gronov., 

 which is Bidens chnj sunt he mo ides. Ilelepta rjrandijiora, &c., Raf. Neog. — "Dry or moist 

 groiind, Canada to Florida. 



H. SCabra, Dunal. Ilispidulous-scabrous, especially the leaves, 2 to 4 feet high : leaves 

 from broadly ovate aud suljcordate to ovate-lanceolate, the npper occasionally entire : rays 

 oblong, nearly or quite an inch in length : akeues smooth, but the angles above pubescent 

 when young, the summit usually bearing an obscure or evident aud irregular coroniform 

 chaffy pappus, or sometimes 2 or 3 conspicuous and rigid teeth ! Otherwise as in the fore- 

 going, into which it may pass. — Mem. Mus. 1. c. 56, t. 4; Hook. Fl. i. 310; DC. Prodr. 

 V. 550, excl. syu. II. cancscens, Don. H. hevis, var. scahra, Torr. & Gray, Fl. ii. 303. — 

 W. New York to Saskatchewan, Missouri, and Arkansas. 



H. gracilis, Nutt. Slender, a foot or two high : leaves ovate-lanceolate to lanceolate (2 or 

 3 inches long), aud with somewhat cuueate base, hispidulous-scabrous or almost smooth : 

 heads very much smaller, barely 3 or 4 lines high, and the fewer (5 to 10) rays 5 to 8 lines 

 long: akenes of//, scahra. — Trans. Am. Phil. Soc. n. .ser. vii. 353. H. Uevis, var. minor, 

 Hook. Comp. Bot. Mag. i. 98. H. Urn-is, var. gracilis, Torr. & Gray, Fl. ii. 303. — Dry and 

 shaded ground, Georgia aud W. Florida to Louisiana and Arkansas, Gates & Jeicett, Drum- 

 mond, Ciniiss, &c. 



H. parvifolia, Gray. Slender, a foot or two high, from cinereous-puberulent aud some- 

 what scabrous to nearly glabrous and green : leaves deltoid-lanceolate or rhomboid-lanceolate 

 or approaching deltoid-ovate, irregularly dentate with few or several. teeth, or some entire, 

 an inch or two long : head barely half-inch high : rays oval or oblong, half or two-thirds 

 inch long : akeues glabrous but dull and rugulose-scabrous, the summit evenly truncate. — 

 PI. Wright, ii. 86; Rothr. in Wheeler Rep. vi. 159. //. bnphthalnioidcs. Gray in Bot. Mex. 

 Bound. 88, not Duual. — Canons and beds of streams, Arizona, \Vri(jIi1, Thurber, &c. (Lower 

 Cal. & adj. Mex.) 

 H. BUPiiTHALMOinES, Duual, of Mexico and S. America, aud H. Axxua, Hem.sley (which 



may be the //. canescens, HBK., tliat being said to have an annual root, as has Parry & 



Palmer's no. 431), have puberulejit or papillose-pubescent akenes. 



87. TETRAGONOTHECA, Dill. (Terpaywi/os, four-angled, er'iKrj, case, 

 i. e. involucre.) — Erect perennial herbs, all N. American, with striate stems ; 

 the leaves all opposite, mostly sessile or connate-amplexicaul, thinnish, dentate 

 or sinuate-pinnatifid ; heads rather large, on slender peduncles terminating the 

 stem or branches ; both disk- and ray-corollas light yellow, nervose (the ligules 

 5 to 10-nerved, and the usual 5 nerves of the throat of the disk-corollas not 

 rarely doubled), marcescent and persisting almost to the maturity of the akenes. 

 Fl. summer. — Dill. Elth. ii. 378, t. 283; Linn.; Benth. & Hook. Gen. ii. 3G7. 

 Tetragonotheca & Halea, Torr. & Gray, Fl. ii. 303, 304. 



§ L Akenes very thick, obscurely 4-sided or almost terete, wholly destitute of 

 pappus : tube of the corolla villous below : stem simple : involucre very saliently 

 4-angled in the bud. 



T. helianthoides, L. Villous with .somewhat viscid hairs : stem a foot or two higli : leaves 

 ovate or rhomboid-oblong, closel}^ sessile by a narrow base, dentate, 4 to 6 inches long : lobes 

 of the involucre and 6 to 9 rays about an inch long. — Spec. ii. 903 ; DC. Prodr. v. 552 ; 

 Torr. & Gray, 1. c. Pol'/ninla Tetrar/onotheca, L. Syst. ; Abbot, Ins. & PI. Georg. ii. t. 69; 

 Schkuhr, Haudb. t. 263. SUphiuni Tetragonotheca, Gtertn. Fruct. t. 171. — Dry ground, 

 Virginia to Florida. 



§ 2. Akenes distinctly 4-sided and the sides striate (somewhat pubescent), 

 moderately narrowed from the truncate summit to base : pappus pluvisquamellate 



