ou 



POPULAR FLORA. 193 



Calyx of 5 (rnrely 4) nenrly similar pepnls, all more or less petal-like. 



Stamens 4 to 9: akene generally small: cotyledons narrow, (Pohjfjonnm) IvNOTWEia). 



Stamens 8: styles 3: akene triangular, shaped like a beechnut, much longer than the 

 calyx: cotyledons very broad and folded in the mealy albumen: root annual: 

 leaves nearly halberd-shaped : flowers white, corymbed, {Faijojyyrum) *Buckwiii-:at. 



Calyx of 6 sepals, and 



All alike and petal-like ^ white): stamens 9: styles 3, {Rheum) ^Rhubakk. 



Three outer ones herbaceous and spreading: three inner larger, especially after flow- 

 ering, when they close over the triangular akene: flowers dioecious: leaves 

 sour, eared or halberd-shaped, {Rumex, § AcetoscUu) Soiujel. 



Flowers perfect or polygamous: leaves bitter: coarse herbs, {Rumex) Dock. 



Knotweed. Pohjgonum. 



* Flowers single or several together in the axils of the leaves, greenish or whitish: sheaths (stipules) 



cut-fringed or torn into narrow shreds. 



1. Common Knotweed, Knotgrass, or Goosegrass. Spreading on the ground, small ; leaves 



sessile, lance-shaped or oblong, pale ; a variety has nearly upright stems and oblong or oval leaves. 

 The commonest weed in yards and waste places. P. aviciUare. 



2. Slender K. Upright, somewhat branched; leaves linear, acute, sheaths fringed. Dry soil. P.tinue. 



* * Flowers in terminal heads, spikes, or racemes. 



•*- Xot twining nor climbing, and leaves not heart-shaped nor arrow-shaped: calyx petal-like and 



5-parted, except in Xo. 10. 



3. Oriental K. or Prince's Feather. Tall annual, 4° to 7° high; leaves ovate; spikes of rose- 



colored flowers long and nodding; stamens 7; akene flatfish. Gardens. F. orieniale. 



4. "Water K. Stems floating In water, or rooting in mud, or upright; leaves lance-shaped or oblong; 



spike thick and short; flowers rose-red; stamens 5; styles 2. P. amphiblum. 



5. Pennsylvania K. Stem upright, l°too°]iigh; leaves ]ance-shape<l ; spike oblong, thick, erect, 



its peduncle. beset with club-shaped bristles or glands; flowers rose-colored; stamens 8; akene 

 flat. ^loist ground. F. Pennsylvdnicum. 



6. Lady's-Tiiumb K. Stems, &c. like the last and next, but no bristles on the peduncle; leaves with 



a darker spot on the upper side; spike short and thick, erect; flowers greenish-purple; stamens 

 G. Very common in waste places. P. Persicaria. 



7. Smartweed or "Water-Pepper K. Upright, annual, 1° or 2° high, very acrid and biting to the 



taste; leaves and also the greenish sepals marked with fine transparent dots; spikes short but 

 loo^e, drooping; akene flattish or bluntly triangular. Sloist ground, common in waste places, 

 yards, and near dwelUngs. P. nijdropiper. 



8. "Wild Smartweed K. Upright, 1° to 3° high from a perennial root, biting like the last, and the 



leaves dotted; spikes very slender, erect, whitish or flesh-color; stamens 8; styles 3; akene sharply 

 triangular. Wet places. *  P. acre.. 



9. Mild Water-Pepper K. Upright, 1° to 3° high; often creeping at the base and rooting in water; 



leaves roughish, not biting, narrowly lance-shaped; spikes slender, erect, rose-color; stamens 8; 

 style 3-cleft at the top ; akene sharply triangular. Shallow water. P. hj/drcpipero)fks. 



10. "\'iRGiNiA K. Stem 2^ to 4''high, angled; leaves large, ovate or lance-ovate, taper-pointed; flow- 



