POLYGONACEAE. 65 



FAMILY 1. POLYGONACEAE. BUCKWHEAT FAMILY. 



Plants various in habit. Leaves with manifest, usually sheathing, 

 stipules (oereae) and inflorescence not involucrate, or the stipules obsolete 

 and the inflorescence involucrate. 



Flowers or flower-clusters Involucrate : stamens 9. 1. EBIOGONUM. 



Flowers or flower-clusters not Involucrate : stamens 4-8. 

 Hypanthium little developed, not investing the achene. 

 Internodes of the stem and branches partially adnate. 

 Inner sepals not flmbriate, sometimes conspicuously 



accrescent. 



Sepals (inner) accrescent: achene included. 2. POLYGONELLA. 



Sepals not accrescent : achene partially exposed. 3. DELOPYEUM. 

 Inner sepals flmbriate. 4. THYSANELLA. 



Internodes of the stem and branches not adnate. 5. PEESICAEIA. 



Hypanthium strongly developed, investing the achene. 6. COCCOLOBIS. 



1. EBIOGONUM Michx. Herbs, partially woody plants or shrubs. 

 Leaves mainly alternate, without oereae, the stipules scale-like. Flowering- 

 stems with alternate or whorled bracts. Flowers involucrate. Hypanthium 

 jointed to a pedicel which is subtended by a minute bractlet. Sepals 6, often 

 unequal. Stamens 9. Gynoecium 3-carpellary : stigmas capitate. 



1. E. tomentosum Michx. Basal leaves 5-18 cm. long; blades oblong to 

 spatulate: flowering-stems 4-12 dm. tall, the leaves in whorls of 3-5; blades 

 ovate to obovate or oblanceolate : involucres about 4 mm. high: sepals white, 

 the inner ones becoming 6-7 mm. long, broadly cuneate to truncate at the 

 base, tomentulose without: achenes 5 mm. long. Pinelands. 



2. POLYGONELLA Michx. Woody plants. Leaves alternate, jointed 

 near the top of the oereae. Flowers in spreading racemes. Sepals mainly 

 white or pink, the 3 inner accrescent. Stamens 8: filaments irregular, the 

 inner ones more or less dilated. 



1. P. brachystachya Meisn. Plant slender, 2-6 dm. tall, copiously branched: 

 leaves 5-13 mm. long, rather persistent: racemes short and relatively stout: 

 inner sepals becoming ovate: achenes rhombic, 1.5 mm. long. Pinelands. 



3. DELOPYRUM Small. Herbs resembling Polygonella in habit, but 

 annual and loosely branched. Flowers in erect racemes. Sepals essentially 

 unchanged in shape at maturity. Stamens 8: filaments various, the 3 inner 

 more or less dilated below. 



Inner sepals oblong or nearly so at maturity : oereae eciliate. 1. D. gracile. 



Inner sepals linear-spatulate at maturity : oereae eciliate. 2. D. cttiatum. 



1. D. gracile (Nutt.) Small. Stems 3-17 dm. tall: stem-leaves with oblong, 

 spatulate, or linear-spatulate blades 1-2.5 cm. long: stipe-like base of the 

 hypanthium less than 1 mm. long: inner sepals becoming 1.5 mm. long, 

 slightly longer than the outer: achenes about 2.5 mm. long. [Polygonella 

 gracilis (Nutt.) Meisn.] Pinelands. 



2. D. ciliatum (Meisn.) Small. Stems 6-13 dm. tall: stem-leaves with fili- 

 form or linear-filiform blades 2-4 cm. long: ocreolae acuminate: hypanthium 

 less than 1 mm. long: inner sepals becoming 2.5 mm. long, much longer than 

 the outer: aehenes about 2.5 mm. long. {Polygonella ciliata Meisn.] Pine- 

 lands. 



4. THYSANELLA A. Gray. Woody plants. Leaves alternate, jointed 

 near the top of the fringed ocreae. Flowers polygamo-monoecious, those of 

 the upper racemes fruit-producing. Sepals white or pink, not accrescent, the 

 3 inner at least pectinate-fimbriate. Stamens 8. Filaments slender. 



Flora of Miami 5 



