348 



MANUAL OF BOTANY 



numerous, with or without wings, exalbuminous ; iDlacentation 

 axile ; embryo straight, with flat leafy cotyledons, and the radicle 

 towards the hiluni. 



Diagnosis. — Herbs or shrubs, with entire exstipulate usually 

 opposite leaves. Calyx tubular, ribbed, persistent, bearing the 

 deciduous petals and stamens ; the latter being inserted below 

 the petals. Anthers 2-celled, adnate, burstmg longitudinally. 

 Ovary superior, with axile placentation ; style 1. Fruit mem- 

 branous, dehiscent, surrounded by the non-adherent calyx-tube. 

 Seeds numerous, exalbuminous. 



Distribution and Numbers. — The greater 

 number are tropical plants, but some are also 

 found in temperate^ regions, as, for instance, in 

 Europe and North] America. One species only, 

 Ly thrum Salicaria, hitherto has-been found in 

 Australia. Illustrative Genera: — Lythrum, 

 Linn.', Lawsonia, Linn. There are about 250 

 species. 



Properties and Uses. — These plants are 

 chiefly remarkable for the possession of an 

 astringent principle,^and^for their value in dye- 

 ing. 



Order 145. Onagrace^, the Evening Prim- 

 rose Order. — Character. — Herbs or shrubs. 

 Leaves alternate or opposite, simple, exstipulate, 

 without dots. Calyx superior, tubular, with the 

 limb usually 4-lobed, or sometimes 2-lobed ; in 

 aestivation valvate ; or rarely the limb is absent. 

 Petals usually large and show}^ generally regular 

 and equal in number to the divisions of the 

 cah'x, twisted in aestivation, and inserted into 

 the throat of the cal3X ; rarely absent. Stamens 

 definite, 2, 4, or 8, or rarely by abortion 1, in- 

 serted with the petals into the throat of the calyx; filaments 

 distinct ; 2Jollen trigonal. Ovary inferior, 2— 4-celled ; placentas 

 axile ; stijle 1, filiform ; stigma lobed or capitate. Fruit cap- 

 sular, or succulent and indehiscent, 2— 4-celled. Seeds nume- 

 rous, without albumen ; embryo straight. 



Diagnosis. — Herbs or shrubs, with simple exstipulate dotless 

 leaves. Calyx superior, 2 — 4-lobed, valvate in aestivation. Petals 

 usually equal in number to the lobes of the calj^x, with a twisted 

 aestivation, or rarely absent. Stamens few, inserted into the 

 throat of the calyx with the petals. Ovary inferior, 2 — 4-celled; 



Fig. 1110. Verti- 

 cal section of 

 the flower of a 

 species of Wil- 

 low-herb (Epi- 

 lohium). 



