I 82 



Fam. I 7. Chenopodiaceae. 

 (Plates 45, A 1), 46.) Flor. Cap. Vol. v, Sect. 1, 4.3 



Herbs or half-shrubs with alternate, exstipulate leaves 

 and greenish or yellowish, inconspicuous flowers. Flowers 

 bisexual or unisexual and then monoecious or dioeeious. 



Perianth herbaceous or occasionally absent, 

 mostly 5-parted (rarely + — 2-parted), persistent, mostly 

 enlarging with the fruit and enclosing it. Stamens 

 as many as the perianth-segments, opposite them, inserted 

 at their base, incurved in the bud. Pollen grains globose, 

 with numerous pores (20 — 40). Ovary superior or nearly 

 so, free, unilocular; ovule solitary, campylotropous, 

 attached to a basal funiculus; styles 2 4. Fruit a nut, 

 enclosed in the persistent perianth ; pericarp membranous. 

 Seed either with farinaceous perisperm (not endosperm) 

 or without reserve-tissue. Embryo peripheric, clasping 

 the perisperm, or, when this is absent, spiral or folded. 



Ecology. Many species are halophytes, occurring in 

 the neighbourhood of the sea or in other saline localities, 

 especially also in arid regions, where the soil is often rich 

 in chlorides (common salt) and sulphates (Glauber's salt). 

 The adaptations to their existence in such regions are 

 numerous and often very elaborate. Various kinds of 

 hairs occur on leaves and stems, often as a woolly layer 

 [Salsola Zeyhei~i). Others produce inflated, bladder-like, 

 pedicillate hairs, which contain a saline sap when young, 

 but shrivel up later on, forming a white, powdery (mealy) 

 layer on the leaf, thus removing the excess of saline 

 matter from the tissues, while by the same device the 

 leaves obtain protection against excessive transpiration 

 {Atriplex Halimus). Others are succulents, where the 

 excess of salt is removed with the old leaves, e,g, Salsola 

 aphylla (Ganna). The wood of the shrubby species 

 shows a remarkable anomaly, the flbrovascular bundles 

 being scattered as in monocotyledonous stems or arranged 

 in several circles. 



(Plate 45 is facing page 1 86.) 



