140 WILLOW : BIRCH [CH. 



catkin of a Willow, we find in its axil a single more or 

 less flask-shaped ovary, stalked or sessile, subtended by 

 one or two minute, yellow, club-shaped bodies termed 

 honey-glands, as in Fig. 39. 



There is nothing to which we can give the name 

 of petals or sepals, and no stamens are present in 

 this normal female flower: it is achlamydeous and uni- 

 sexual. 



Simple as it is, however, the fact of there being a 

 developed closed ovary, formed of two carpels, as betrayed 

 by the double stigma and the two parietal placentae, 

 bearing several ovules, stamps this as a more highly 

 differentiated flower than that of any Conifer. 



And similarly with the male flowers : each scale of 

 a male catkin of the Willow bears in its axil two (or in 

 rare cases 1, 3, or 5) stamens subtended by one or two 

 minute honey-glands as before, and the differentiation of 

 the stamen into a filament and anther marks the flower 

 simple as it is as more highly specialised than the 

 male flower of the Gymnosperm. The flowers of the 

 Poplar are similarly simple, with a few differences in 

 details concerning the shape, &c., of the glands and the 

 numbers of the stamens, as shown in Fig. 39. 



Here, again, we have flowers of extremely simple 

 structure, and unisexual and achlamydeous. 



Let us take as a further example the Birch. 



On dissecting off the scale of a female catkin we here 

 find, instead of the simple bract of the Willow with one 

 axillary flower, a complex of one larger median bract 

 (b in Fig. 40) bearing two lateral bracteoles (a and /3, 

 Fig. 40) on its inner face, and each of these subtends 

 an ovary : there is no perianth. 



Here, then, the principal catkin-scale bears in its axil 

 a small inflorescence of three achlamydeous and unisexual 



