AMARANTACEAE 187 



Ecology. Although the flowers are mostly incon- 

 spicuous they appear to be visited by insects, while some 

 are evidently anemophilous. The fruitlets of most species 

 are easily carried about by the wind or passing animals, as 

 the persistent perianth develops various kinds of wings, 

 hairs or hooks, while in other cases the entire glomerule 

 breaks away, and the hooks derived from the barren 

 flowers secure the dispersal. 



Owing to these excellent contrivances for transport 

 and considerable resistancy against drought, various species 

 of AmarcmtuS) Pupalia and Alternanthera i::i have become 

 troublesome weeds. Others are cultivated in gardens for 

 ornamental purposes, e.g. Celosia argentea var. cristata 

 (the cockscomb) and Gomphrena globosa (the globe 

 amaranth) ; also several species of Alternanthera on 

 account of their variegated leaves. 



KEY TO THE GENERA. 



[Compare Flor. Cap. Vol. v, Sect, i, 403.] 

 Tribe I. Celosieae. 

 Leaves alternate. Stamens 5 ; anthers 2-celled, each cell 2-locular. 

 Ovary many-ovuled. Fruit mostly many-seeded (rarely 2 seeds only). 



A. Staminal tube short, without appendages between the stamens. 



1 species in S. A., C. trigyna. 1. Celosia L. 



Flor. Cap. 404. 



B. The staminal tube with 5 bifid petaloid appendages. 



Endemic. 7 species. E, No. 



2. Hermbstaedtia Reichenb. 

 Flor. Cap. 405. 

 Tribe II. Amaranteae. 



Anthers 2-celled, each theca 2-locular; ovary i-ovuled. Fruit i-seeded. 

 A. Flowers unisexual. Stamens free, staminodes o. Ovule erect, 

 funicle short. 



Several cosmopolitan species in S. A. 



1 perhaps indigenous. 3. Amarantusf L. 



Flor. Cap. 408. 



* Alternanthera sessilis and A. Achyrantha, the "amarantltS weed" See Agric. 

 Journ. (C. C), Vol. 37, p. 267 (1910). 



j" The introduced species Amarantus retroflexus and A. paniculatus, as well as the 

 indigenous A. Thunbergii y are known in the Transvaal under the names pig weed and 

 mistbreede- 



24—2 



