18 ORNAMENTAL CACTI. 



also furnish wood for rustic picture frames, ornamental pincushions, 

 trays, inkwell stands, and the like. To a limited extent the wood of 

 the taller growing species forms material in the shape of poles for the 

 construction of fences and temporary huts. 



HEDGES. 



Because of their animal-resisting armor of spines, combined with 

 their habit of growth, certain species of cacti are naturally adapted 

 for use as efficient hedge plants wherever they grow in the open 

 throughout the year. The one species most commonly used in Mex- 

 ico for this purpose is the organo {Cereus marginatus), PL VI, so 

 called because of its fancied resemblance to the pipe of an organ. It 

 branches freely from the base near the surface of the ground, and these 

 branches immediately assume an upright habit of growth. Growing 

 closely together they soon produce an impenetrable barrier. Its 

 habits of growth recommend it, since there are scarcely any branches 

 above the base and these never spread and cover any great area, 

 thus making a compact, dense, and comparatively narrow hedge. 

 Cereus stellatus and C. weberi are also used in the regions where they 

 are abundant as native plants, but they have the disadvantage of 

 making a thicker and more open hedge and consequently cover more 

 ground. Where narrowness of the hedge is of minor importance, 

 many of the taller growing species of Opuntia make an equally 

 serviceable barrier and are at all times decorative, especially when 

 bearing an abundance of flowers and fruits. 



DECORATIVE VALUE OF CACTI. 



It is not intended to convey the idea that cacti, as a whole, can 

 hope to rival many other groups of plants in gorgeous display. For 

 the most part they lack the foliage that lends so much to the value 

 of other plants, and in most instances the flowers, when present, are 

 either too small, too few (Pis. VII, VIII, IX, and X), or too short 

 lived to be considered of any great worth. In some of the climbing 

 species of Cereus and in Phyllocactus the flowers attain a very con- 

 siderable size, and their waxlike texture and pure whiteness or deli- 

 cately tinted red, pink, or cream colors present a combination that 

 always calls forth exclamations of wonder and pleasant surprise. 

 Many forms bloom at night, and their flowers are always white and 

 to a slight degree pleasantly fragrant. The flowers are usually pro- 

 duced in periods, each period lasting from one to three or four days. 

 At such a period the plants, if mature and vigorous, will bear a 

 large number of flower buds, which open in the evening after sunset 

 and close with the approach of strong morning light, never again 

 to open. The following night other buds will bloom, and so on 



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