POLYGONACEAE . 373 



sometimes shorter on the branchlets, obtuse, 3-5-nerved, leathery, exceeding the inter- 

 nodes except on the npper part of the stem : ocreae cylindric, sliglitly oblique, not pointed, 

 increasing in length toward the upper part of the stem : racemes very dense, 2-3 cm. long, 

 disposed in ovoid panicles : ocreolae funnelform, densely imbricated, slightly pointed : 

 pedicels jointed at the middle : calyx purple or purplish, 2.5-3.5 mm. long: outer sepals 

 slightly accrescent : sepal-wings oblong, 4 mm. long : achenes narrowly oblong, acuminate 

 at both ends, 4 mm. long, brown. 



On sand hills, near the coast, Florida. Summer and fall. 



4. GONOPYRUM F. & M. 



Shrubby herbs, with rigid conspicuously jointed stems. Leaves alternate : blades 

 narrow, often nearly terete, somewhat fleshy, jointed to the ocreae. Ocreae cylindric. 

 Flowers perfect, on solitary jointed pedicels. Ocreolae numerous. Sepals 5, petaloid, 

 persistent, unchanged at maturity or the 3 inner developing wings. Stamens 8 : filaments 

 various, the 3 inner dilated at the base. Ovary 3-angled : styles 3, manifest : stigmas 

 capitate. Achene 3-angled, mainly invested by the calyx. Embryo in the face of the mealy 

 endosperm. 



Annual : outer sepals not reflexed ; inner sepals not becoming conspicuously larger than the outer. 



1. G. articulatum. 

 Perennial : outer sepals reflexed ; inner sepals developing large wings. 2. G. Americanum. 



1. Gonopyrum articulatum (L. ) F. & M. Annual, wiry, glaucous. Stems 1-3 dm. 

 tall : leaf-blades linear or linear-subulate, 1-2.5 cm. long, tiliform on account of the revo- 

 lute margins : ocreae slightly expanded at the summit : racemes many-flowered, 2.5-4 cm. 

 long, erect, panicled : ocreolae contiguous or imbricated : pedicels spreading or deflexed, 

 longer than the peduncles : calyx pink : sepals erect or slightly spreading in fruit, none de- 

 veloping conspicuous wings : achenes narrowly ovoid, 2 mm. long, pointed, brown, smooth 

 and shining. [Polygonella articulata (L. ) Meisn. ] 



On sandj- shores along or near the Atlantic coast. Maine to Florida, and along the Great Lakes. 

 Summer and fall. 



2. Gonopyrum Americanum F. & M. Perennial by a long root, glaucescent. Stems 

 5-12 dm. tall, somewhat flexuous, often sparingly branched : leaf-blades linear or linear- 

 spatulate, 1-3 cm. long, more or less clustered on short branches, obtuse and revolute 

 at the apex : ocreae cylindric, slightly split on one side, scarious-margined : racemes 2.5-7.5 

 cm. long, disposed in compound panicles : ocreolae densely imbricated : pedicels rigid, 

 divergent, terminating somewhat shorter peduncles : calyx white or pink, the 2 outer 

 sepals reflexed in fruit, the 3 inner developing suborbicular wings : achenes elliptic-ob- 

 long, not quite 3 mm. long, chestnut-brown, pointed at both ends, smooth and shining. 

 \_Polygonella ericoides Engelm. & Gray ; P. Meisneriana Shuttl. ] 



In sandy soil, Missouri to Georgia, Alabama and Texas. Summer and fall. 



5. THYSANELLA A. Gray. 



Annual caulescent herbs. Stem erect, nearly strict, terete, the branches partially 

 adnate to the internodes. Leaves alternate : blades narrow, sessile. Ocreae cylindric, ob- 

 lique at the top, fringed with long bristles. Racemes rather dense, disposed in panicles, 

 the upper ones fertile, the lower sterile. Flowers polyganio-monoecious, on club-shaped 

 pedicels about as long as the peduncles. Ocreolae obliquely-funnelform, prolonged into 

 long bristles. Sepals 5, unchanged in fruit, unequal, the 2 outer cordate, the 3 inner 

 pectinate-fimbriate, or in fertile flowers all fimbriate. Stamens 8 : filaments filiform, 

 flattened and spirally twisted. Ovary 3-angled : styles 3, distinct or nearly so : stigmas capi- 

 tate. Achene 3-angled. Embryo in an angle of the seed without the mealy endosperm. 



1. Thysanella fimbriata (Ell.) A. Gray. Glabrous. Stem erect, 1.5-6 dm. tall, 

 nearly strict, paniculately branched above : leaf-blades narrowly linear, 2-6 cm. long, 

 acute, more or less distinctly 3-ribbed, inconspicuously jointed near the top of the ocreae : 

 ocreae 5-13 mm. long : racemes 1-8 cm. long : ocreolae imbricated : calyx white or pink, 

 the outer sepals oblong-sagittate, cordate, the inner always fimbriate, or all fimbriate in 

 fertile flowers : styles ^ as long as the achene : achenes pyramidal-ovoid, 3-angled, 2 

 mm. long, dark brown, long-pointed, smooth, shining, the angles more or less margined. 



In dry pine lands, Georgia and Florida. Summer and fall. 



