Tetragonotheca. COMPOSITE. 255 



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

 anthoides, L. Hort. Ups., & Spec. ii. 904; Michx. Fl. ii. 130; L'Her. Stirp. t. 45. Silphium 

 helianthoides, L. Spec. ii. 920, pi. Gronov. S. solidaginoides, L. Spec. 1. c. Rudbeckia oppositi- 

 folia, L. Spec. 1. o. 907, pi. Gronov. Helianthus Icevis, L. Spec. ed. 2, 1278, excl. syn. Gronov., 

 which is Bidens ckrysanthemoides. Selepta grandiflora, &c, Raf. Neog. — Dry or moist 

 ground, Canada to Florida. 



H. scabra, Dunal. Hispidulons-scabrous, especially the leaves, 2 to 4 feet high: leaves 

 from broadly ovate and subcordate to ovate-lanceolate, the upper occasionally entire •. rays 

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

 when young, the summit usually bearing an obscure or evident and 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. syn. H. canescens, Don. H. Icevis, var. scabra, 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), and with somewhat cuneate 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 H. scabra. — Trans. Am. Phil. Soc. n. ser. vii. 353. H. Icevis, var. minor, 

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

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

 mond, Curtiss, &c. 



H. parvifolia, Gray. Slender, a foot or two high, from cinereous-puberulent and 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 : akenes glabrous but dull and rugulose-scabrous, the summit evenly truncate. — 

 PI. Wright, ii. 86 ; Rothr. in Wheeler Rep. vi. ] 59. H. buphthalmoides, Gray in Bot. Mex. 

 Bound. 88, not Dunal. — Canons and beds of streams, Arizona, Wright, Thurber, &c. (Lower 

 Cal. & adj. Mex.) 

 H. BUPHTHALMofDES, Dunal, of Mexico and S. America, and H. Annua, Hemsley (which 



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



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



87. TETRAG-ONOTHECA, Dill. (Terpayun/os, four-angled, 6^, 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. 367. 

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



§ 1. 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 high : leaves 

 ovate or rhomboid-oblong, closely 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. Poli/mnia Tetragonotheca, L. Syst. ; Abbot, Ins. & PI. Georg. ii. t. 69 ; 

 Schkuhr, Handb. t. 263. Silphium Tetragonotheca, Gsrtn. 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 plurisquamellate 



