8. H. cistifòlium, Lam.! Stems mostly simple, herbaceous, with a somewhat woody base, angled with 4 very narrow salient lines (1--2° high); leaves narrowly oblong to nearly linear (1--3´ long), sessile with a somewhat clasping base; the cyme naked, compound, usually many-flowered; _sepals ovate; pods depressed-globular or ovoid-conical_; seeds large, oblong, very rough-pitted. (H. sphærocarpon, _Michx._)--Rocky river-banks, S. W. Ohio, to Iowa and southward. July--Sept.--Flowers small. 9. H. ellípticum, Hook. Stem simple, herbaceous (10--20´ high), obscurely 4-angled; _leaves spreading, elliptical-oblong_, obtuse, usually narrower toward the subclasping base, thin; cyme nearly naked, rather few-flowered; _sepals oblong; pods ovoid, very obtuse_; seeds minutely striate.--Wet places, New Eng. and Penn. to Minn., and northward. July, Aug.--Petals light yellow, 3´´ long. 10. H. virgàtum, Lam. Stem slender, strict, simple, sharply 4-angled, herbaceous (1--2° high); _leaves ascending_, opaque, ovate or oblong-lanceolate, acute (½--1´ long), closely sessile by a broad base; cyme compound, naked, the scattered flowers racemose on its ascending branches; _sepals herbaceous, erect_, enclosing the ovoid pod; _styles 3, separate_, with capitate stigmas. (H. angulosum, _Michx._)--Wet pine barrens of N. J. and southward; Ky. July--Sept.--Petals copper-yellow, 4--5´´ long. § 3. _Stamens very many, in 3 or 5 clusters; styles 3, separate and usually diverging; pod 3-celled; calyx erect; petals and anthers with black dots; perennials._ H. PERFORÀTUM, L. (COMMON ST. JOHN'S-WORT.) Stem much branched and corymbed, somewhat 2-edged (producing runners from the base); leaves elliptical-oblong or linear-oblong, with pellucid dots; petals (deep yellow) twice the length of the _lanceolate acute sepals_; flowers numerous, in open leafy cymes.--Fields, etc. June--Sept.--Too well known as a pernicious weed, which it is difficult to extirpate. Juice very acrid. (Nat. from Eu.) 11. H. maculàtum, Walt. Conspicuously marked with both black and pellucid dots; stem terete, sparingly branched; leaves oblong or lance-ovate, the base either obtuse or somewhat clasping; _flowers crowded_ (small); _petals pale yellow_, much longer than the _oblong sepals_, styles mostly not longer than the pod. (H. corymbosum, _Muhl._)--Damp places; common. July--Sept.--Leaves larger and flowers much smaller than in the last; petals 2--3´´ long, marked with black lines as well as dots. The ordinary northern form differs from the typical southern one in the shorter style and the more oblong less clasping leaves. § 4. _Stamens 5--12, distinct or in 3 clusters; pod 1-celled, with 3 strictly parietal placentæ; styles short, distinct, with capitate stigmas; petals oblong or linear; sepals narrow, erect; slender annuals, with 4-angular branches; flowering all summer._ [*] _Stem simple or loosely branched; leaves linear to ovate, spreading._