Polygonum?}, polygon ace^e. 287 



2. POLYGONUM, Linn. 



Perianth of 5, rarely fewer, segments, all equal, or the 2 or 3 outer ones en- 

 larged. Stamens 8 or sometimes fewer in the same species. Styles 3 or 2, 

 sometimes united at the base ; the stigmas entire. Nut triangular or flattened, 

 enclosed in or surrounded by the persistent perianth. — Herbs varying much 

 in habit. Flowers small, pale green or red, or with white edges, clustered or 

 rarely solitary in the axils of the upper leaves, or in little clusters surrounded 

 by a sheathing bract, and collected in terminal spikes, heads, or panicles. 



A large genus, with almost the ubiquitous range of the Order. 



Flowers in axillary clusters. Stems prostrate LP. 



Flowers in terminal spikes. Stems erect, ascending, or climbing.. 

 Stipules sheathing, wholly scarious, truncate or ciliate. 

 Styles 3. 



Stems very hispid. Peduncles glandular-hairy 2. P. viscosum. 



Stems and peduncles glabrous. Sheathing stipules hairy, 



with long bristles at the top 3. P. barbatum. 



Styles 2. 



Spikes slender and interrupted. Perianth glandular-dotted. 



Stipules shortly ciliate 4. P. Hydropiper. 



Spike slender but continuous. Perianth not dotted. Stipules 



not ciliate 5. P. glabrum. 



Spike short, oblong or cylindrical. Perianth slightly glandu- 

 lar-dotted. Stipules scarcely ciliate 6. P. lapathifolium . 



Stipules green and spreading at least at the top. 



Tall, erect, hairy plant. Stipules sheathing at the base. Leaves 



ovate-cordate 7. P. orientate. 



Glabrous prickly climber. Stipules spreading from the base. 



Leaves triangular 9. P. perforatum. 



Flowers in little heads, in dichotomous panicles. Stems erect or 



climbing 8. P. chinense. 



1. P. plebeium, Br. ; Meisn. in DC. Prod. xiv. 94. A much branched 

 prostrate annual, 6 in. to 1 ft. long, glabrous, or the branches slightly hoary. 

 Sheathing stipules short and scarious, ragged at the edges, but not ciliate. 

 Leaves linear, narrow-oblong, or slightly spathulate, rarely above ^ in. long. 

 Flowers small, in clusters of 2 to 5 in the axils of most of the leaves. Styles 

 3. Fruiting perianth not a line long; the segments green, with a narrow 

 white edge. Nuts triangular, very smooth and shining. — P. herniarioides, 

 DC; Meisn. in DC. Prod. xiv. 94. P. Miquelianum, P. effusum., P. Roxburghii> 

 P. illecebroides, P. cliffortioides, P. Perrottetii, and P. ciliosum, Meisn. I.e. 

 93, 94, and 95. 



In cultivated and waste places, Champion and others. Exceedingly common all over tro- 

 pical Asia, extending into Africa and Australia. After a careful examination of very nume- 

 rous specimens, neither Dr. Hooker nor myself have been able to detect any tangible differ- 

 ences between the Egyptian, Indian, and Australian specimens. All come very near to the 

 common European P. avicutare, but the nuts are always very smooth and shining, besides 

 that the stems are shorter, more leafy and prostrate, and the flowers considerably smaller. 



2. P. viscosum, Ham. ; -Meisn. in DC. Prod. xiv. 102, An erect or 

 ascending annual, 1 to 2 ft. high, the stem hispid with long stiff spreading 

 hairs, intermixed with a glandular pubescence. Stipules loosely sheathing, 

 rather short, hispid and ciliate. Leaves lanceolate, glabrous or hairy. Spikes 



