GINKGO 
393 
colours indicate insect-fertilisation, but nothing is known about the 
details. Saintpaulia [q>v.) and others exhibit two types of floral 
symmetry on the same plant. 
None of the G. are economic plants; many are hothouse favourites. 
Classification and chief genera (after Fritsch) : 
“ The relationships to allied orders, especially Scrophulariaceae, 
Orobanchaceae and Bignoniaceae, are so close that it is almost im- 
possible to draw the dividing lines. The B. are most sharply 
marked off by the structure and formation of their fruit and seed, and 
often by their divided leaves. The O. might very well be placed in 
G. as a parasitic sub-order. The placentation and structure of the 
ovary is the chief mark of distinction between the G., O., and S.” 
I. CYRTANDROIDEAE (ovary free, superior): Ramondia, 
Saintpaulia, Didymocarpus, Streptocarpus, Aeschynanthus, 
Besleria, Cyrtandra, Columnea. 
II. GESNERlOILkEAE (ovary more or less inferior) : Achi- 
menes, Isoloma, Gesneria. 
[Placed in Personales by Benth. -Hooker, in Personatae by Warming.] 
Gethyllis Plum, ex Linn. Amaryllidaceae (i). 9 sp. Cape Col. 
Geum Linn. Rosaceae (ill. 6 c). 36 sp. N. and S. temp., arctic. G. rivale 
L., the water avens, with a thick rhizome and large protogynous firs, 
is frequent, and G. urbanum L., wood avens, with smaller nearly 
homogamous firs., abundant in Brit. Both sp. with many others of 
the genus, have a hook on each achene of the fruit to aid in distribu- 
tion. If the style be examined in a newly opened fir. it will be found 
to have a Z-like kink in it. The lower half of this after fertilisation 
gets larger and more woody, while the upper half finally drops off. 
Gigantochloa Kurz. Gramineae (xm). 5 sp. Indo-mal. Giant bamboos. 
Gilia Ruiz, et Pav. Polemoniaceae. 90 sp. temp, and subtrop. Am. 
Gillenia Moench. Rosaceae (1. 1). 2 sp. N. Am. 
Ginkgo Linn. Coniferae (Taxaceae of Eichler, but better placed in 
a separate order Ginkgoaceae ; see C. for genus characters, and cf. 
An?i. of Bot. 1900, p. 108). 1 sp. G. biloba L. (Salisburia adi anti- 
folia Sm.), China, Japan, the maiden-hair tree. Its leaves resemble 
those of the maiden-hair fern. In former ages G. was widely spread. 
Sp. occur in the Tertiary strata of England. There are Hong 5 and 
‘short’ shoots, the latter bearing a few scale leaves and several of 
the curious green leaves, with their forked venation (cf. Cycads and 
Ferns). Leaves deciduous; the short shoot bears a new set each 
year. Firs, dioecious, in the axils of the uppermost scales or lowest 
green leaves of a short shoot (so that their position differs from the 
usual one in Conifers with long and short shoots). The male has 
the form of a loose catkin of sta. The female is long-stalked, with two 
ovules borne on rudimentary cpls. (see order). Seed usually one only, 
with fleshy aril. The seed is ‘ ripe ’ and falls from the tree before 
fertilisation of the ovule takes place; this process, and the embryo- 
