PART III 

 GINKGOACE.E 



GINKGOACE^. 



Ginkgo, Ksempfer. 

 A monotypic genus on which the family Ginkgoacece is founded, 

 differing from Taxacece and Pinacece in several essential charac- 

 ters, notably in its wide, flattened leaves and motile male sperms. 

 By the latter character it is allied to Cycadacece and to the Ferns. 

 The single species is the sole survivor of one of the most interesting 

 families of trees, widely distributed in the temperate regions of 

 both hemispheres in earlier geological times, and once even in- 

 cluded in the forest flora of the British Isles. 



Ginkgo biloba, Ksempfer. (Fig. 120.) 

 Maidenhair Tree. 



Salisburia adiantifolia, Smith. 



A deciduous tree up to 100 ft. high with a trunk 18-20 or 

 more ft. in girth, often slenderly pjrramidal and sparsely branched 

 when young, becoming spreading with a dense head in after-life. 

 Bark greyish, deeply furrowed on old trees. Branches irregularly 

 whorled or produced at indefinite intervals, some erect and 

 forming duplicate leaders. Branchlets horizontal or drooping, 

 beset with short spur-like shoots, as in larch and cedar, which 

 may continue to produce clusters of leaves annually for many 

 years and then suddenly lengthen out into long shoots bear- 

 ing scattered leaves. Buds conical, short-pointed, with bright 

 brown scales. Leaves on stalks up to 3 in. long, fan-shaped, 

 resembling the pinnule of a maidenhair fern, usually 2-3 in. 

 across, but on vigorous young trees sometimes 6-8 in. across, 

 light green when young, darker towards midsummer, golden in 

 autumn ; the upper margin divided into two large lobes, usually 

 undulated or irregularly notched, with no midrib, but with 

 numerous branching parallel veins ; stomata on both surfaces. 

 3Iale and female flowers produced on different trees. Male 

 flowers appearing early in May from the short shoots as pendulous 

 catkins (3-6 on one shoot), bearing numerous loosely arranged 

 stamens. Female flowers arising from short shoots in pairs or 

 in threes, each consisting of a long stalk bearing on either side 



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