538 
POLYGALACEAE 
Floral diagram of Poly gala myr- 
tifolia (after Eichler) ; the gland d 
as in P. Chamaebuxus. Petals 
and bracts black ; the missing petals 
represented by dotted lines, the 
missing sta. by *. 
Infl. a raceme, spike, or panicle, with bracts and bracteoles. Hr. di- 
plochlam., medially zygomorphic. K ^ 
usually 5, rarely (5), the 2 inner sepals 
(alae) often large and petaloid; C 5, 
rarely all present usually only 3 — the 
lowest and two upper — more or less 
joined to sta.-tube, the median anterior 
petal keel-like and often with a ter- 
minal brush ; A in two 5-merous 
whorls, usually only 8, or 7, 5, 4 or 
3, usually united below into an open 
tube; G (5 — 2), usually (2), antero- 
posterior; ovary 2-loc. with 1 anatro- 
pous pendulous ovule in each loc. 
(rarely i-loc. with go ovules). Cap- 
sule, nut or drupe. Endosperm or 
not. The floral mechanism, like the 
structure, resembles that found in 
many Leguminosae. Chief genera : 
Polygala, Securidaca, Xanthophyl- 
lum. Placed in Polygalinae by Benth. -Hooker, in Aesculinae by 
Warming. [See Krameria.] 
Polygaleae (Benth. -Hooker) = Polygalaceae. 
Polygalinae (Benth. -Hooker). The 3rd cohort of Polypetalae (p. 132). 
Polygonaceae. Dicotyledons (Archichl. Polygonales). 30 gen. with 
750 sp. chiefly N. temp. ; a few trop., arctic, and S- hemisph. Most 
are herbs whose leaves (exc. Eriogoneae) possess a peculiar sheathing 
stipule or ochrea (ocrea) clasping the stem above the leaf-base. This 
forms a characteristic feature of the order. The infl. is primarily 
racemose, but the partial infls. are usually cymose. [See Eriogonum.] 
The firs, are 5 , regular, cyclic or acyclic. The former have usually 
the formula P 3 + 3, homochlamydeous ; A 3 + 3, G (3); but many 
vary from this type. Oxyria is 2-merous; others, e.g. Eriogonum, 
Rheum, have ‘ dedoublement* of the outer sta. The acyclic firs, have 
P 5, arranged according to the 2/5 phyllotaxy (e.g. Polygonum), 
A 5 — 8, G (3). Ovary i-loc. with 1 erect orthotropous ovule and 3 
styles. The firs, are pollinated by wind or by insects. The fruit is 
almost always a triangular nut, with smooth exterior. The seed con- 
tains an excentric curved or straight embryo surrounded by mealy 
endosperm, sometimes ruminate. The fruits are usually wind-distri- 
buted; the commonest type of mechanism is that the persistent 
perianth forms a membraneous wing round the fruit. Other fruits 
are provided with hooks for carriage by animals. See individual 
genera or Dammer in Nat. PJi. 
Classification and chief genera (after Dammer) : 
A. Flower cyclic, endosperm not ruminate. 
