Shrubs and Vines 



and incisions correspond with surprising exactness. 

 But in the sweet fern, the incisions, which are very 

 deep, and reach almost to the mid-rib, are as uniformly 

 alternate on the two sides. A little thought will ex- 

 plain this almost solitary exception to the rule. The 

 incisions are so numerous and deep that the mid-rib 

 would be much weakened and liable to break if they 

 exactly coincided, but acquires rigidity by the simple 

 device of alternating the incisions, whereby the mid- 

 rib is strengthened on one side when weakened on 

 the other. I shall always have more respect for this 

 despised weed after such proof of painstaking in its 

 construction. 



For those whose grounds adjoin a lake or pond, the 

 familiar button-bush, Cephalanthus occidentalis ', is worth 

 considering. It grows in water, has luxuriant, dark- 

 green foliage, and showy clusters of white flowers, 

 densely massed into spherical heads ; the leaves are op- 

 posite or whorled. 



I have seen no shrub in the Park whose glossy ever- 

 green foliage surpasses that of Mahonia aquifolium, per- 

 haps the most desirable low species of its sort. The 

 leaf is pinnate, and each leaflet is the duplicate of the 

 English holly leaf, but with a lustre that can scarcely be 

 rivalled ; and being in the barberry family, it is often 

 called holly -leaved barberry. It comes from the Far 

 West, and, though called evergreen in the books, it does 

 not prove so in the Park. Its short racemes of small 

 yellow flowers are produced early in spring, and followed 

 by blackish berries. It should be included in every list 

 of lawn shrubbery, however small. 



171 



