e 



■^^■^ POLYGONACE^. [Polygonum. 



light green above, paler beneath, raaAed on both sides with depressed dots or 

 glands, flat or slightly wavy only, their margins minutely spinuloso-ciliate, thf 

 n'i'"' ^^'"s uf the leaf very indistinct above, more conspicuous underneath. 

 Uchrece close, destitute of transparent glands or dots, membranaceous, truncate, 

 with many pellucid ribs, terminating in long fringe-like hairs or cilise, much more 

 conspicuous than in P. Hydropiper from their greater length. Spikes axillary 

 and terminal, on long compressed peduncles, straight and very slender, almost 

 hliform, erect, not drooping or at most slightly nodding, often interrupted, a 

 small knot of one or more flowers being commonly found separated from the 

 superior and continuous portion of the spike by an interval more or less remote. 

 Flowers smaller thjin in P. Hydropiper, somewhat loosely imbricated, deep rose- 

 red Bracts coloured. Nuts broadly ovate or ovato- elliptical, pointed, partly and 

 rather obtusely trigonate, the rest more or less compressed and lenticular, deep 

 purplish or brownish black, very smooth and shining. 



This species stands in nearly" the same relation to P. Hydropiper that P dume- 

 torum and P. Convolvulus do to one another. 



** Styles 3. Stamens mostly 8. Fruit triquetrous. " Flowers axillary."— Br. Fl. 



e. v. aviculare, Ij. Knot-grass. Vect. Wire-weed. "Leaves 

 elliptic-lanceolate, stipules much shorter than the internodes with 

 few distant simple nerves, stem herbaceous, achene about as long 

 as and covered by the perianth striated with raised points."— £r 

 M. p. 354. E. B. t. 1252. 



a. Stems erect, vei-y slender and wiry. 



^. Stems prostrate, spreading mostly in a circular form ; leaves small, crowded. 



In cornfields, waste places, and by roadsides ; everywhere. Fl. May— Septem- 



a. Abundant in corn-stubble, as at Cowes, &c., &c. 



13. In sandy ground by the sea. Plentiful along the shore between Eyde and 

 Sea View, 1845. 



7. P. Raii, Bab. Bay's Knot-grass. Great Sea Knot-grass. 

 Stem procumbent herbaceous, ochrese 2-lobed ovate acute at length 

 torn with few uribranched distant nerves, flowers axillary, fruit 

 very smooth and shining much longer than the perianth. Bahing. 

 in E. B. Suppl. ii. t. 2085. Linn. Trans, xvii. t. 458. P. avicu- 

 lare c, _Sm. E. Fl. ii. p. 238. P. Roberti, Lois. : Br. Fl. p. 854. 

 P. maritimum, Ray, Syn. p. 147. 



In loose sand or dry waste ground by the sea ; occasionally. FL July — Sep- 

 tember. 0. 



E. Med. — On the shore between Sea View and the Priory, very sparingly. 



W. Med. — On waste ground opposite Plumbley's hotel. Freshwater Gate, and 

 at Brook I find what I believe to be this species. 



A var. of what is probably this species, having remarkably large and broad 

 obuvate leaves, grows by the pathside above the clifl' of Sandown bay, 1845. 



Leaves pale green or somewhat glaucous, mostly longer than the joints of the 

 much-branched stem except in the lower part. Ochrem whitish, torn, the laciniae 

 equal in length to the flowers. Flowers mostly 3 (seldom 5) together in the axils 

 of the leaves, nearly sessile. Perianth with a very broad white border. Fruit 

 large, smooth, destitute of strise, terminating in a rather acute point, much longer 

 than the perianth. 



Our P. Raii and P. maritimum bear the same relation to each other as Sali- 

 cornia herbacea to S. radicans, and it is probable that the latter species of both 

 genera are but perennial varieties of the two former, the stems surviving a mild 

 winter, and acquiring firmness suflicient to resist two or more returns of frost, and 

 finally becoming ligneous through age. Of P. Raii I shall only remark that in 



