70 KEY AND FLORA 



I. RUMEX L. 



Coarse herbs, many of them troublesome ■weeds. Flowers 

 small, usually green or greenish, generally in whorls borne in 

 panicled racemes. Calyx of 6 nearly distinct sepals, the 3 

 inner ones larger and more petal-like than the 3 outer, and one 

 or more of them usually with a little knob or tubercle on its 

 back. Stamens 6; styles 3; stigmas short, fringed. Fruit a 

 3-angled akene, closely covered by the 3 inner calyx lobes, 

 enlarged and known as valves. 



1. R. crispus L. Yellow Dock. Stout, smooth, 3-4 ft. high. 

 Leaves lanceolate, margins very wavy, acute, the lower more or 

 less heart-shaped. Root long, tapering gradually downward, yellow, 

 very tough. Flowers in whorls crowded in long, straight, slender 

 racemes. Valves roundish-heart-shaped, mostly tubercled. A very 

 hardy weed, naturalized from Europe. 



2. R. verticillatus L. Swamp Dock. Perennial. Stem stout, smooth, 

 erect or ascending, 3-5 ft. tall. Lower leaves oblong, obtuse at the 

 apex and usually heart-shaped at the base, long-petioled, often 12-18 

 in. long; upper leaves narrower and often acute at both ends. Flowers 

 bisexual or somewhat monoecious, in dense whorls ; pedicels slender, 

 ^-| in. long, tapering downward, reflexed at maturity. Calyx green, 

 the valves broadly triangular, abruptly pointed, reticulated, a distinct 

 long and narrow tubercle on the back of each. Swamps and wet 

 ground.* 



3. R. Acetosella L. Sheep Sorrel. Erect annual or perennial 

 herbs with creeping rootstooks. Stem simple or branched, smooth. 

 Leaves petioled, narrowly halberd-shaped, aisually widest above the 

 middle, the apex acute or obtuse ; upper stem leaves often nearly 

 linear and not lobed. Flowers dioecious, small, in terminal, naked, 

 panicled, interrupted racemes. Calyx greenish ; the pistillate pani- 

 cles becoming reddish. Fruit less than yV in. long, granular, longer 

 than the calyx. A common weed, naturalized from Europe, in dry 

 fields and on sour soils. Foliage very acid.* 



II. POLYGONUM L. 



Annual or perennial, terrestrial or aquatic herbs, with en- 

 larged joints and simple, alternate, entire leaves ; the sheath- 

 ing stipules often cut or fringed. Flowers bisexual, usually 

 white or rose-colored, each flower or cluster subtended by a 

 membranaceous bract similar to the stipules of the leaves. 



