142 SUMMER FLOWERS. 



cotyledonous. This group includes the Orders numbered from 

 62 to 73. 



* Flowers imperfect or naked (\. e. ivitJiout perianth or 

 glumes) , or consisting of scales. 



t Inflorescence forming dense spikes or heads. 



62. Orontiaceous plants— herbs ; flowers hermaphrodite, spadi- 



ceous, the spadix issuing from a two-edged leaf; perianth 

 scales six, herbaceous ; ovary free, one- or more-celled, with 

 erect ovules. 



63. Typhaceous plants — aquatic herbs ; flowers unisexual, ar- 



ranged on a naked spadix ; scales thin. 



tt Flowers distinct, or in loose spikes. 



64. Pistiaceous plants — floating, stemless, aquatics ; flowers 



borne on the edge of the small scale-like fronds, quite 

 naked. 



65. Naiadaceous plants — floating aquatics, with distinct stem 



and leaves ; perianth of four scales, or wanting ; ovaries 1, 

 2, or 4. 



** Flowers perfect, ivith a petal-like whorled perianth. 

 f Ovary inferior. 



66. Hydrocharidaeeous plants — floating or submerged herbs ; 



flowers regular ; dioecious ; stamens nine or more, free. 



67. Iridaceous plants — herbs ; flowers six-leaved, hermaphro- 



dite ; stamens three, free. 



68. Orchidaceous plants — herbs ; flowers six-leaved, irregular ; 



stamens gynandrous (combined with the style). 



tt Ovary superior. 

 % Ovary syncarpous. 



69. Liliaceous plants — herbs; perianth six-leaved, the sepals 



and petals alike, or nearly so (sometimes combined), regular. 



