ESSENTIAL FLORAL LEAVES. 99 



and female, with carpels only. Several terms used in this con- 

 nection, are given in the following table : — 



'monoecious, with both kinds 

 on same plant, e.g., fir, 

 hazel, arum ; dicccioux, 

 with the two kinds on 

 different plants, e.g., wil- 

 low, nettle, hop. 



Plants possessing 



unisexual flowers are 



unisexual flowers + bi- r 



sexual flowers are Volygamous, e.g., ash. 



The instances mentioned may now be briefly described. 



Fir (fig. 45). — Male cones small, crowded into a cluster on the 

 sides of a shoot which produces leaves beyond it. Dusty when 

 ripe from yellow pollen. Female cones occur singly for the most 

 part. They take two years to mature their seeds, and in early 

 summer cones in three stages may be found on the same plant. 

 (1.) Small green cones with pink-tipped scales, occurring close to 

 the ends of the youngest shoots, and belonging therefore to the 

 current year. (2.) Larger green cones, belonging to the previous 

 year, and situated on older shoots. (3.) Brown wood} 1 - cones with 

 ripe seeds, placed on still older parts of the stem, and two years 

 old. 



Hazel. — The pendent catkins seen in March are male inflores- 

 cences, and consist of a large number of scaly bracts. Each of 

 these bears four stamens on its under side, but, as each of these 

 is forked, there appear to be eight. Their true nature is shown 

 by the fact that they bear but one anther lobe. The female cat- 

 kins are very small, and being closely surrounded by bracts, look 

 like buds. Each of them consists of five or six flowers, the only 

 parts of which are visible externally resemble a number of small 

 threads, bright pink in colour. 



Arum (fig. 33). — The upper part of the spadix is club-shaped 

 and brightly coloured. Lower clown comes a circlet of aborted 

 male flowers, a little distance beneath which is a lot of small male 

 flowers, each of which consists of one stamen. These are crowded 

 into a ring round the stem. A ring of female flowers forms the 

 base of the inflorescence. It is separated by an interspace from 

 the preceding. Each female flower has a single carpel, but, like 

 the male flowers, is devoid of perianth. Those at the upper part 

 of the ring are aborted. 



Willow. — Both male and female catkins are here short and 

 upright. The former are readily distinguished by their bright 

 yellow colour, and consist of a large number of male flowers with- 

 out perianth. Each consists of two long stamens placed in the 

 axil of an oval bract provided with long hairs. At the base of 



