GJELLER UP I A 2 9 1 



hair fern, and very often with a deep median division, forked in 

 venation (cf. ferns and cycads), scattered on long shoots, or crowded 

 at the apex of short shoots, which sometimes elongate into long. 

 Below the 1. on the short shoot are a few scale 1. Fls. dioecious, in 

 the axils of the uppermost scales or lowest green 1. on a short shoot 

 (position different from that usual in Coniferae with long and short 

 shoots). 4 a stalked central axis, bearing scattered rather loosely 

 disposed sta., each of which is a slender filament ending in an apical 

 scale and two or more pollen-sacs with longitudinal opening. The 

 pollen grain forms a rudimentary prothallus of a few cells, and the 

 generative nuclei produce two large spirally coiled spermatozoids 

 (cf. cycads). The ? has the form of a long stalk with two term, 

 elliptical ovules enclosed at the base by a collar-like envelope repres. 

 a reduced carpellary 1. Each ov. consists of a nucellus surrounded 

 by one integument, which in the ripe seed forms a thick fleshy aril- 

 like covering round a hard woody shell. In the mature ov. the 

 greater part of the nucellus tissue is reduced to a thin papery layer 

 enclosing a large embryo-sac with usually i archegonia. Fert. occurs 

 before or after the ovule has fallen from the tree. The embryo has 

 2 cots. 



The seed is edible, and yields an oil, and the timber is useful. 

 Ginkgo thus represents a very old type, with relationships to 

 the Cycadales and the Filicales. Fossil species are found in the 

 Carboniferous, 1'ermian, Triassic, and Jurassic, and in the Tertiary 

 of England. 



For details see Coulter and Chamberlain, Morphology of Gymno- 

 sperms; Fujii on floral morphology in Bot. Mag., Tokio, 1895; 

 Seward and Gowan in Ann. Bot. 1900, p. 108 ; Ikeno on fertilisation 

 in Ann. Set. Nat. Bot. xin. 1901, p. 303; Lyon on embryology in 

 Minn. Bot. Stud. in. p. 275. 



Ginkgoaceae. The only fam. of Ginkgoales, with one gen. Ginkgo 

 (q-v.), formerly placed in Coniferae. 



Ginkgoales. The 2nd class of Gymnosperms. 



Ginora L. (Ginoria Jacq.). Lythraceae. 7 Mex., W.I. 



Ginseng, Aralia Ginseng Baill. 



Giorgiella De Wild. Passifloraceae. i Congo. 



Gipsywort, Lycopus mropaeus L. 



Giraldia Baroni (Atractylis p.p. EP.). Compositae (n). i China. 



Giraldiella Damm. Liliaceae (v). i China. 



Girardinia Gaudich. Urticaceae (i). 6 trop. As., Afr. Stinging 

 hairs. 



Gireoudia Klotzsch Begonia L. p.p. (Begon.). 



Girgensohnia Bunge. Chenopodiaceae (B). 4 W. and C. As. 



Gironniera Gaudich. Ulmaceae. 8 Indomal., Polynesia. 



Gisekia (Giesekia) L. Phytolaccaceae (Aizoaceae BH.}. 5 trop. Afr. 

 and As. 



Githago Adans. = Lychnis L. (#//.) = Agrostemma L. (Caryoph.). 



Githopsis Nutt. Campanulaceae (i). i California. 



Giulianettia Rolfe. Orchidaceae (n a. in), i New Guinea. 



Givotia Griff. Euphorbiaceae (A. n. 5). i S. India, Ceylon. 



Gjellerupia Lauterbach. Opiliaceae. i New Guinea. 



192 



