SALICINEJE. 



649 



mit. In the genera amhora and monimia, the 

 involucre is persistent; it even enlarges greatly, 

 and becomes fleshy in the first of these genera. 

 The fruits, which in amhora are contained in 

 the substance of the walls of the involucre, are 

 Eo many small unilocular one-seeded drupes. 

 The seed is composed of a rather thin proper 

 integument, covering a very thick fleshy endo- 

 sperm, in the upper part of which is placed an 

 embryo which has the same direction as the 

 seed. 



The genera have been divided into two tribes: 



1. AmboreJ! : anthers opening by a longitu- 

 dinal groove; seeds reversed. Amhora, monimia, 

 ruizia. 



2. Atherospekme^ : anthers opening from 

 the base to the summit, by means of a valve ; . 

 seeds erect. Pavonia, atherosperma, citrosma. 



The monimiae are much allied to the urticeas, 

 with which several of their genera were formerly 

 united; but they differ from them especially in 

 having their seeds furnished with a very large 

 endosperm, and in having their ovules pendent 

 and not erect. The same character also separ- 

 ates them from the laurinese, which theyapproach 

 in the structure of their stamina in the tribe of 

 atherospermeje. The properties of the species 

 are little known. 



SalicinbjE, Rich. This family is composed 

 of the genera salix and populus, and contains 

 large trees, with alternate, simple leaves, fur- 

 nished with caducous stipules. The flowers are 

 unisexual, and disposed in cylindrical or egg- 

 shaped catkins. The male flowers are composed 

 of from two to twenty stamina, placed in the 

 axilla of a scale, or upon its upper surface. The 

 female flowers consist of a fusiform pistil, ter- 

 minated by two bipartite stigmas, situated in 

 the axilla of a scale, and sometimes accompanied 

 at their base by a cup-shaped calyx. The ovary 

 has one or two cells containing a considerable 

 number of erect ovules, attached to the bottom 

 of the cell, and the base of two parietal tropho- 

 sperms. The fruit is a small, elongated capsule, 

 with one or two cells, containing several seeds 

 surrounded by long silky hairs, and opening by 

 two valves. The embryo is erect, homotrope, 

 destitute of endosperm. 



The salicineiB, a dismemberment of the amen- 

 tacese, form a group which is very distinct in the 

 form of their fruit. 



This family affords some useful and ornamental 

 trees. The bark is generally astringent and 

 tonic. It is employed in tanning, and that of 

 some species, especially of salix helix, has of late 

 acquired some celebrity as a substitute for Per- 

 uvian bark in fevers. 



Myrice<b, Rich., (Causuarinea:, Mirbel.) 

 With the exception of the genus causuarina, 

 which, in its general aspect, resembles a gigantic 

 eguisetum, the myricese are trees or shrubs, with 



alternate or sparse leaves, with or without stipules. 

 Their flowers are always unisexual, and most 

 commonly dioecious. The male flowers, dis- 

 posed in catkins, are composed of one or more 

 stamina, often collected upon a branched andro- 

 phorum, and placed in the axilla of a bractea. 

 The female flowers, which are also in catkins, 

 are solitary and sessile in the axilla of a bractea 

 longer than themselves. Each flower is com- 

 posed of a lenticular ovary, containing a single 

 erect ovule. The style is very short, and sur- 

 mounted by two long subulate, glandular stig- 

 mas. Externally of the ovary are two, three, 

 or a greater number of hypogynous, persistent 

 scales, which are sometimes united to the fruit. 

 The fruit is a kind of small monospermous, 

 indehiscent nut, sometimes membranous, and 

 winged upon its margins. The seed which it 

 contains is erect; its integument immediately 

 covers a large embryo, having a direction en- 

 tirely the reverse of that of the seed. 



This family, which is formed of genera that 

 are sometimes placed in the family of amentacete, 

 is allied to the celtidese and betuliness, but diifers 

 from the former in its flowers being in catkins, 

 and always unisexual, and its erect ovule, and 

 from the latter in its unilocular ovary, and its 

 embryo destitute of endosperm. 



Their properties are generally aromatic and 

 resinous. A wax is obtained from the berries 

 of myrica ceri/era. 



Betuline^, Rich. Composed of trees with 

 simple, alternate leaves, accompanied at their 

 base by two stipules. Flowers unisexual, dis- 

 posed in scaly catkins. In the male catkins, 

 each scale, which is sometimes formed of several 

 scales united, bears two or three flowers which 

 are naked, or have a calyx with three or four 

 deep divisions. The number of stamina is vei-y 

 variable in each flower. The female catkins are 

 egg-shaped, or cylindrical, and scaly. At the 

 inner base of each scale are from one to three 

 naked, sessile flowers, presenting a free, com- 

 pressed ovary, with two cells, containing each a 

 single ovule attached towards the upper part of 

 the dissepiment, and surmounted by two elon- 

 gated, cylindrical and glandular stigmas. The 

 fruit is a scaly cone, the woody or merely car- 

 tilaginous scales, bear at their base one or two 

 smaU. unilocular akenia, which aremonospermous, 

 through abortion, and membranous on the edges. 

 The seed is composed of a large embryo without 

 endosperm, having the radicle superior. 



The two genera almcs and betula constitute this 

 family, which differs from the salicinese in having 

 its ovary furnished with two monospermous 

 cells, its indehiscent fruits, and its seeds, destir 

 tute of the long hairs which cover those of the 

 salicinese. The myracese are also closely allied 

 to the betulinese, but their ovary is always uni- 

 locular, and their ovule erect. This family, like 



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