LXXIII, AMENTACE. 403 
Male catkins cylindrical, usually pendulous. 
Three distinct flowers, each with 4 stamens, under each scale of 
the male catkins. Female catkins small, ovoid ., 4 . 2, ALNUS. 
Stamens 6 to 12 within each scale, not in distinct flowers. 
Scales of the male catkins stalked. Femalecatkins cylindrical 3. Betuna, 
Scales of the catkins sessile. 
Stamens at the base of the scale. Female catkins loose, with 
narrow scales . - ; Z j 3 ‘ Z ‘ ‘ 
Stamens on the scale itself. Female catkins minute ses- 
sile and budlike ry Tinka ‘ Fi - - ; ; . 5. CORYLUS. 
Scales of the male catkins narrow-linear, or divided, or very minute. 
Anthers small, on slender filaments, 
Flowers diecious. Catkins, both male and female, cylindrical, compact, 
and usually silky-hairy. 
Catkin-scales entire. Stamens 2, rarely 3 to 5, with1 or 2 gland- 
4, CARPINUS. 
MU MAICIESCALCS ta) 0k ee my we ~~} 8, BALERS 
Catkin-scales jagged. Stamens several, in an oblique, cup- 
shaped perianth . ° ‘ ‘ ; ; . ° é » 9. Popunvs. 
Flowers monecious. 
Male catkins slender and interrupted. Female flowers in small, 
sessile or shortly-stalked clusters. a F . : P 
Male catkins globular, on pendulous stalks. Females erect, 
globular, softly hairy . : a : ‘ : / - 6. Fagus. 
Tree or shrub, in fruit. 
Capsules (in catkins) opening in 2 valves. Seeds minute, with a 
tuft of long, cottony hairs. 
Scales of the catkin entire. Leaves on short or rather stiff stalks. 8, SAaunix. 
Scales of the catkin jagged. Leaves on long stalks, very broad, 
shaking with the wind . ‘ . . : . . ° . 9. PoruLvs. 
Nuts 1-seeded. 
Nuts small, in compact catkins. 
Nuts slightly succulent, and resinous outside . ° ° - 1, Mynica. 
Nuts flat and quite dry. 
Scales of the catkins thin and deciduous. Nuts winged . .. 3. BETULA. 
Scales of the catkins hard, remaining after the nuts havefallen 2, ALNUS. 
Nuts solitary, or in clusters, or in loose spikes, wholly or partially 
enclosed in an involuere. 
Nuts small, in loose spikes, each in a 3-lobed, leafy involucre . 4. 
Nuts solitary or clustered, each in an involucre adhering to it at 
' the base, with leafy, jagged lobes .-:. - : P Coryruvs. 
6. 
7. QUERCUS. 
CARPINUS. 
Nuts (acorns) projecting from a short, cup-shaped involucre . QUERCUS. 
Nuts completely enclosed ina prickly involucre . : : ° Faaus. 
These nine genera are distributed by modern botanists into four tribes 
or orders: Myricacr®, limited to Myrica; BETULACEA, including Alnus 
and Betula; CUPULIFERZ, comprising Carpinus, Corylus, Fagus, and 
Quercus; and SALIcINE®, for Salix and Populus. 
_ Among trees generally planted in Britain, belonging to exotic genera of 
Amentacee or their allies, are the Spanish Chestnut (Castanea), with the 
flowers nearly of an Oak, but the nuts completely enclosed in a prickly 
involucre, as in Fagus; two or three species of Plane (Plantanus), with 
both male and female catkins globular and pendulous, the flowers inter- 
mixed with bristly hairs, and differing slightly from the family in their 
albuminous seeds ; and two or three species of Walnut (Juglans), which in 
their pinnated leaves and more perfect perianth show an approach to 
Terebinthacee. 
I MYRICA. GALE. 
Shrubs, with resinous, dotted leaves. Flowers diccious, in short, sessile 
catkins ; the scales imbricated, without inner scales. Male catkins with 4 
or 8 stamens within each scale, the anthers nearly sessile, and no perianth. 
Females with 2 ovaries within each scale; perianth adhering to the base of 
Dd 2 
