Tetragonotheca. COMPOSITE. 255 



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

 anthoides, L. Hort. Ups., & Spec. ii. 904; Michx. ¥\. ii. 130; L'Her. Stirp. t. 45. Si/phium 

 helianthuides, L. Spec. ii. 920, pi. Grouov. S. solidaginoides, L. Spec. 1. c. Rudbeckia oppositi- 

 Jhlla, L. Spec. 1. c. 907, pi. Grouov. Helianthus heius, L. Spec. ed. 2, 1278, excl. syn. Gronov., 

 wliich is Bidcns chri/santhe moides. Ilelepta grandijiora, &c., Raf. Neog. — Dry or moist 

 groiiud, Canada to Florida. 



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

 t'ruiii uroadly ovate aud subcordate to ovate-lanceolate, the upper occasionally entire : rays 

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

 when young, the summit usually bearing au 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. //. cancscens, Don. //. Icevis, var. scabra, Torr. & Gray, Fl. ii. 303. — 

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



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

 3 inches long), aud 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 //. scabra. — Traus. Am. Phil. Soc. n. ser. vii. 353. //. kevis, var. minor, 

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

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

 mond, Ciirtiss, &.C. 



H. parvifolia, Gray. Slender, a foot or two high, from cinereous-puberuleut 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-tliirds 

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

 PI. Wriglit. ii. 86; Rothr. in Wheeler Rep. vi. 159. //. buphfhal moides, Gray in Bot. Mex. 

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

 Cal. & adj. Mex.) 

 H. BUPiiTHALMofDES, Duual, of Mcxico and S. America, and H. Annua, Hemsley (which 



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



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



87. TETRAGONOTHECA, Dill. (Tcrpaywvo?, four-angled, O/jKr], 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, uervose (the ligules 

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

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

 Fl. summer. — Dill. Elth. ii. 378, t. 283; Linn.; Benth. & Hook. Gen. ii. 367. 

 Tetragonotheca & Halea, Torr. «fc 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 l)y 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; 

 'J'orr. & Gray, 1. c. Poli/mnia Tetragonotheca, L. Syst. ; Abbot, Ins. & PI. Georg. ii. t. 69 ; 

 Schkuhr, Ilandb. t. 263. Silphium Tetragonotheca, Gasrtn. 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 



