374 DICOTYLEDONES. 







frequently valvate and folded, or simply valvate in aestivation. 

 The number of stamens varies. The free gynoeceum is unicar- 

 pellate and has 1 ovule. The fruit is a nut, but becomes a false 

 drupe, since the lower persistent portion of the perianth becomes 

 fleshy (as in Neea, where this fleshy part is almost always crowned 

 by the upper persistent part of the perianth. In the majority of 

 the Mirabileae the lower part liecomes the dry anthocarp, while 

 the upper petaloid part falls away after flowering). Finally, a 

 peculiar involucre is formed around the flowers by free or 

 united floral-leaves. The majority are herbs, some are trees 

 (Pisonia, etc.) ; Bougainvillea is a liane. The stems are often 

 nodose and swollen at the nodes ; the leaves are simple, penni- 

 nerved, scattered, or opposite, without stipules. In some, the vascular 

 bundles are scattered ; stem anomalous. 



Mirabilis ; the structure of the stem is abnormal. Dichasial 

 branching with continuation from the second bracteole, thus form- 

 ing unipared scorpioid cymes. The perianth is petaloid, funnel- 

 shaped, and has a folded and twisted aestivation resembling that 

 of the corolla of the Convolvulacece ; the upper coloured portion 

 falls off after the flowering. Outside, and alternating with it, is 

 a 5-partite, sepaloid involucre of 5 spirally- placed floral-leaves. 

 Oxybaphus ; the involucre envelops 1-3 dichasial flowers. 

 JBougainvillea-, the involucre is rose-coloured, 3-leaved, and en- 

 velops 3 flowers (placed laterally ; the terminal flower wanting). 

 The leaves of the involucre in Boerhaavia, Pisonia, Neea, and others 

 are reduced to teeth or scales. 



157 species ; mostly in tropical countries, and especially S. Am. Species 

 of Mirabilis (Am.) are ornamental plants. Them is found in Neea the'ifera 

 Oersted (discovered by Lund in Lagoa Santa, Brazil), which may be used as a 

 tea-plant. 



Order 8. Aizoacese. Only 3 ivhorls are found in the flower, which alternate 

 with one another when their leaves are equal in number. The first is sepaloid, 

 the third one the carpels, and the intervening one is either uncleft, in which 

 case it is developed as stamens, or it is divided into a large number of members 

 which then all become stamens (arranged in groups), or the outermost ones 

 become developed as petals. The fruit is most frequently a capsule with 

 several loculi. Most of the species are herbs with thick, fleshy stems, and 

 exstipulate leaves. The structure of the stem is usually anomalous. 



i. AIZOIDE^E have hypogynous or perigynous flowers with (4-) 5 perianth- 

 leaves; stamens single, or (by splitting) in groups of 2-3, alternating with the 

 perianth-leaves. The gynoeceum (with 3-5 carpels) has 3-5 loculi in the ovary, 

 and most frequently numerous ovules in each loculus, borne on the central 

 placenta formed by the edges of the carpels. The fruit is a capsule. The 



