520 LXXXVII. POLYGONACE^E [Polygonum 



tropous. Nut hard, usually enclosed in the calyx, seed erect, radicle superior, 

 albumen mealy or horny. 



Perianth of 4 or 5 sepals or segments. 



Nut trigonous or biconvex, included in the more or less 



equally enlarged perianth-segments . . . . 1. Polygonum. 

 Nut flat, enclosed by 2 large reticulate wings (the inner 



sepals) Atkaphaxis (p. 520). 



Nut oblong, densely covered with long branching bristles 



placed in vertical lines 2. Calligonum. 



Nut with 6 broad wings in 2 tiers ...... Pteropyrum (p. 521). 



Perianth of 6 sepals, nut trigonous, included in the 3 inner 



much enlarged membranous sepals .... Bumex (p. 521). 



1. POLYGONUM, Linn. ; Fl. Brit. Ind. v. 23. 



Stipules tubular, membranous. Fl. small, clustered, bracts and bracteoles 

 membranous, ochreate. Segments of a glandular disk often alternating with 

 stamens. Ovary usually trigonous, styles 2 or 3. Nut included in the more 

 or less enlarged perianth. Species 150, in both hemispheres. 



A. Perianth ^ in. across. Hairy. 



1. P. molle, Don. Bashahr (?). Nepal. Sikkim, 4-8,000 ft. Bhutan. Naga hills. 

 A large gregarious trailing shrub, branches stout, softly tomentose with erect or 

 spreading hairs. L. elliptic-lanceolate, softly tomentose beneath. 2. P. rude, Meissner. 

 Khasi hills and hills of Upper Burma. Similar to 1, strigose, hairs on branches 

 reflexed. 



B. Perianth jL- in. across. Quite glabrous. 



3. P. paniculatum, Blume. Garhwal. Nepal. Sikkim, 5-10,000 ft. Naga hills. — 

 Java. L. elliptic-lanceolate, panicle lax, nut entirely included in the perianth. 4. P. 

 frondosum, Meissn. Garwhal and Kumaon 7-9,000 ft. L. ovate, acuminate, panicle 

 compact, nut larger than perianth. 



C. Perianth \ in. across. 



5. P. polystachyum, Wall. ; Collett Simla Fl. 425 fig. 135. Himalaya from Hazara 

 eastwards, 5-15,000 ft. also in the inner arid region, — Afghanistan. Attains 6ft., stems 

 angled, 1. hairy beneath, oblong-lanceolate, base cordate or rounded, stipules ample. 



Atraphaxis spinosa, Linn. ; Boiss. Fl.Or. iv. 1020. Baluchistan. — Afghanistan, Persia, 

 Turkestan, Arabia, Egypt, Songaria. A rigid shrub, branchlets spinescent, 1. thick, 

 glabrous, from obovate to elliptic and almost orbicular, blade J— J in. long, penni- 

 veined, narrowed into a short petiole. Perianth 4-cleft to the base, the outer sepals 

 smaller, in fr. unchanged and reflexed, the 2 inner enlarged into broad-ovate reticulate 

 wings, J in. diam., closely appressed to, but much larger than the flat nut enclosed by 

 them. A. sinaica, is a variety with smaller 1. 



2. CALLIGONUM, Linn. ; Fl. Brit. Ind. v. 22. 

 Species 20, desert regions of Africa, Western and Central Asia. 



C. polygonoides, Linn. ; Brandis F. Fl. 372. — Syn. C. comosum, L'Her. 

 Vern. PhoJc, phog, Pb. 



A rigid glabrous, almost leafless shrub, sometimes a small tree, trunk 2-3 ft. 

 girth, heartwood dark brown, very hard, branches grey or reddish-grey, 

 numerous and twisted, branchlets green, mostly fascicled, slender, with a few 

 thin linear-subulate leaves. Fl. small, pink, in fascicles of 2-5 from the axils 

 of the sheathing thin transparent stipules. Perianth deciduous, deeply cleft 

 into 5 thin obtuse membranous segments, red with broad white edges. 

 Stamens 10, filaments dilated and pubescent at base. Nuts oblong, J in. long, 

 densely clothed with long filiform branching bristles placed in 8-16 vertical 

 lines, bases thickened and confluent along these lines, so as to form irregularly 

 shaped crests. 



