TREES AND SHRUBS. 407 



also by the presence of the " female " flowers, i.e. those whose 

 anthers fall off without having opened. 



The ovary grows into a brown globular spiny fruit (a 

 capsule, though differing from most capsules in having a 

 rather fleshy wall), which opens (about October) by three 

 valves and usually contains two seeds.] 



[394. The Lime. This tree (Pig. 173) grows "wild" in 

 a few of the southern counties, and is sometimes supposed to 

 be a native ; but this is doubt- 

 ful, since the seeds do not 

 germinate in uncultivated soil. 

 The leaves are heart-shaped, 

 with serrated edges. 



Its flowers, which bloom in 

 June and July, have five sepals, 

 five petals, many stamens, and 

 a five-celled ovary with two 

 ovules in each. They are of 

 a greenish yellow colour, and 

 have a long leaf -like bract at- 



, j , , . , . Fig. 173. The Lime Leaves and 



tached to the axis of the in- Fiowei-s. 



florescence (a cyme) . They are 



also very fragrant, and produce abundance of nectar, and are 

 consequently very attractive to insects. The fruits are nuts, 

 and the persistent bract forms a wing which aids in their 

 dispersal by wind.] 



[395. Common Lilac (Syringa vulgaris), a native of Persia 

 and Central Europe (introduced into Britain about 1600), 

 forms a shrub or small tree (up to 20 feet), which grows 

 rapidly (as much as a yard per year for the first three or 

 four years), but does not last very long about 20 years in 

 rich soils, but 40 or 50 in dry poor soils (why this difference 

 in duration ?) ; it is well known for its handsome appearance 

 when in leaf and its abundant and beautiful flowers. It sends 

 up suckers profusely in all directions ; why do gardeners 

 clear these away as they appear, when a fine tree is desired ? 



The leaf has a long stalk ; the blade, usually heart-shaped 

 but rather variable in outline, is thin and has its surface 

 smooth and its edge entire. The leaves are in crossed pairs. 



