402 THE CATKIN FAMILY. 
LXXII. AMENTACEE. THE CATKIN FAMILY. 
Trees or shrubs, with alternate flat leaves, usually with sti- 
pules, and small, unisexual flowers, in cylindrical, oblong, or 
globular spikes, called catkins, which are usually dense with 
closely packed, scale-like bracts, rarely loose, or with minute 
deciduous scales. Stamens in the male catkins 2 or more 
(rarely united into 1) within each scale, usually accompanied 
by 2 or more smaller scales, either distinct or forming in a _ 
few cases an irregular or oblique perianth, or rarely entirely 
deficient. Female catkins either like the males, with 1, 2, or 
3 flowers within each scale, or reduced to a sessile bud, with 2 
or 3 ‘flowers in the centre, surrounded by the lower empty 
scales of the catkin; within each scale are also usually 2 or 3 
inner scales. Perianth none, or closely combined with the 
ovary, with a minute, free, or entire toothed border. Ovary 
1-celled or several-celled, with 2 or more styles, always result- 
ing in a l-celled fruit, which is either a l-seeded nut, or a 
several-seeded capsule opening in 2 valves. The catkin-scales, 
or the inner scales, or both, usually persist, and are sometimes 
enlarged into an involucre, either around or under the fruit 
Seeds without albumen, at least in the British genera. 
An extensive family, widely distributed over the globe, but chiefly in 
the temperate regions of both hemispheres, where it often constitutes 
a large proportion of the forest-trees. Minor differences, chiefly in 
the female flowers, have required its division into several independent 
families, but for the purposes of this work it forms a natural as well as 
a distinct group. Among the few British plants that have their inflor- 
escence at all resembling catkins, Hippophae is readily distinguished by 
the berry-like fruits and scurfy foliage, Ulmus by its hermaphrodite 
flowers, Humulus by its opposite leaves, and Conifere by their peculiar 
foliage, independently of the important character of the naked seeds. 
Tree or shrub, in flower. 
Seales of the male catkins broad, imbricated. Anthers longer than 
their filaments. 
Male and female catkins short, sessile, and erect ‘ Paar . 1. MYRIOA. 
Male catkins cylindrical, usually pendulous. 
Three distinct flowers, each with 4 stamens, under each scale of 
the male catkins. Female catkins small, ovoid . : . 2 ALNUS. 
Stamens 6 to 12 within each scale, not in distinct flowers. 
Scales of the male catkins stalked. Female catkins cylindrical 3. BETULA. 
Scales of the catkins sessile. 
Stamens at the base of the scale. Female catkins loose, with 
narrow scales . s : F i , ; . 4, CARPINUS. 
Stamens on the scale itself. Female catkins minute, ses- 
sile and budlike 
Scales of the male catkins narrow- linear, or divided, or very minute. 
Anthers small, on slender filaments. 
Flowers dicecious. Catkins both male and female, cylindrical, com- 
pact, and usually silky-hairy. 
On 
e 
CORYLUS. 
