74 POLYGON ACE AE 



Plant usually diffuse and emersed; leaves of a lanceolate tj-pe, pubescent, acumin- 

 ate. - 2. P. Aluhlenbergii. 

 Ocreae with spreading foUaceous tops; leaf-blades narrowly oblong or lanceolate 

 (broader in floating forms) , pubescent. 3. P. Harturightii. 

 Racemes axillary as well as terminal, numerous; annuals. 

 Ocreae without marginal bristles. 



Racemes erect; glands on the branches and inflorescence numerous, stalked. 



4. P. omissa. 

 Racemes drooping; glands on the branches and inflorescence sessile. 



Styles united only at the base. 5. P. incarnata. 



Styles united to about the middle. 



Leaves deep green on both sides. 6. P. lapathifolia. 



Leaves pale beneath. 7. P. incana. 



Ocreae bristle-fringed. 



Racemes oblong or cylindric, about 1 cm. tliick in fruit; perianth not punctate, 



usually pink to red-purple. 8. P. Persicaria. 



Racemes slender, loosely flowered, about 5 mm. thick in fruit; perianth white 

 or pale green, copiously punctate. 

 Racemes erect; achenes smooth and shining. 9. P. punctata. 



Racemes nodding at least in fruit; achenes granular and dull. 



10. P. Hydropiper. 



11. BISTORTA (C. Bauliin) Mill. Bistort. 



Racemes not viviparous, not bulblet-bearing, oblong, 1-2 cm. thick. 



Perianth 5-6 mm. long; leaf-blades lanceolate, oblong, or oblanceolate. 



1. B. bistortoides. 



Perianth 3-4 mm. long; basal leaf-blades Unear. 2. B. linearifolia. 



Racemes viviparous, bulblet-bearing below, Unear, 5-8 mm. thick. 3. B. vivipara. 



12. FAGOPYRUM (Tourn.) Mill. Buckwheat. i. F. Fagopyrum. 



13. ACONOGONUM Reichenb. l. A. phytolaccacfoUum. 



14. TRACAULON Raf. Tear-thumb. \. T. sagitiatum. 



15. BILDERDYKIA Dum. False Buckwheat, Bindweed. 



Outer sepals merely keeled at maturity. 1. B. Convolvulus. 



Outer sepals developing conspicuous wings. 2. B. scandens. 



Family .38. CHENOPODIACEAE. Goosefoot Family. 



Embryo annular. 



Stems and branches not jointed; leaves not scale-like. 



Flowers perfect, all with perianth, not inclosed in a pair of bracts. 

 Fruit inclosed in the caly.x. 



Calyx in fruit not transversely winged. 

 Sepals 3-5; stamens 1-5. 



Fruiting calyx herbaceous. 1. Chenopodium. 



Fruiting calyx fleshy, red. 2. Blitum. 



Sepals I; stamens 1. 3. Monolepis. 



Calyx in fruit transversely winged. 



Flowers paniculate; leaves ample, sinuate, flat. 4. Cycloloma. 



Flowers spicate; leaves linear, terete. 5. Kochia. 



Fruit laterally flattened, exserted from the marcescent calyx. 



6. CORIOSPERMUM. 



Flowers monoecious or dioecious; the pistillate inclosed in two accrescent bractlets. 

 Pericarp not hairy. 



Bracts compressed; leaves more or less farinose; testa mostly coriaceous. 

 Pistillate flowers without perianth. 7. Atriplex. 



Pistillate flowers with 2-3 hyaUne sepals shorter than the bracts. 



8. Endolepis. 

 Bracts ob^compressed ; testa membranous. 



Pericarp hastate with crested margins, 2-toothed apex; herbs more or 



less farinaceous, with toothed leaves. 9. Suckley.\. 



Pericarp obovate or orbicular, entire; undershrubs with entire leaves. 



10. Gratia. 

 Pericarp densely hairy, conic; low and tomentose shrubs. 11. Euroti.v. 

 Stems and branches fleshj-, jointed; leaves scale-like; flowers sunk into the rachis of 

 the spike. 

 Flower-clusters decussately opposite; branches opposite. 12. S.\licorxia. 



Flowers spirally arranged ; branches alternate. 13. Allenrolfia. 



Embryo spirally coiled. 



Shrubs with monoecious bractless flowers; staminate flowers in spikes, without peri- 

 anth; pistiUate ones soUtary, axiUary; fruiting calyx transversely winged. 



14. S.\RCOB.\TUS. 



Herbs with perfect bracteolate flowers. 



Fruiting calyx transversely winged; leaves spiny. 15. S.\lsol.\. 



Fruiting calyx not winged; leaves fleshy, not spiny. IG. Dondia. 



