THE PLAN OF THE FLOWER. §5 



3. Bedandancies, 



flj In the multiplication of organs, 

 6, In appendicular organs. 



4. Union of parts. 



o, By cohesions, 

 6, By adhesions. 



5. Irregularities of development, 



a, In homogeneous parts, 



b, In the receptacle. 



6. Combined deviations. 



We shall consider these several topics in their order. 



418. The radical numbee of the flowee is that which enumerates the parts 

 composmg^each whorl. It varies from one to twenty, and is expressed thus: 

 ' I V, V, V, etc, which mathematical expressions are to be read by the words, 

 dimerous ((5(f, two, /iipoc, part), or 2-parted ; trimerous, or 3-parted ; 4-merous, or 

 4-parted ; pentamerous, or 5-parted ; 6-merous, or 6-parted, etc. 



419. ExoGENS AND ENDOGENS DiSTiNOuiSHED. Pentamerous {V) flowers, like 

 the rose, flax, when each whorl is (naturally) 5-parted, are more generally charao- 

 teristio of the exogenous" plants, V flowers of the endogens, as the lily, Trillium. 

 The flowers of Fuchsia are V, of Circsea V, and of Hippuris 1 V'. 



420. Deficiencies. Incomplete flowers often occur. They lack some one or 

 more entire sets of organs. When only one of the floral envelops, the calyx, ex- 

 ists, the flower is said to be apetalous or monochamydeom {^2.afiv(, a cloak), as in 

 elm, Phytolacca. These terms are also loosely applied to such plants aa rhubarb, 

 Anemone, liverwort, where the pieces of the perianth are all similar, although in two 

 or three whorls. When the perianth is wl^pUy wanting, the flower is said to be 

 achlamydeous or naJced, as in lizard-tail. (264.) 



267 266 



264, Flower of Saururus (lizard-tail); aohlymydoous. 265, Flower of Fraxinus (ash). 266, 

 Flower of Salix (willow), staminate. 26T, pistillate. 



421. Imperfect flowees are also of firequent occurrence. They are deficient in 

 respect to the essential organs. A sterile or staminate flower (denoted thus $ ) has 

 stamens without pistils. A fertile or pistillate flower (?) has pistils without sta- 

 mens. Such flowers being counterparts of each other, and both necessary to the 

 perfection of the seed, must exist either together upon the same plant or upon sep- 

 arate plants of the same species. In the former case the species is monoecious (8 ) 

 as in oak ; in the latter case dioecious {$ 9 ) as in willow. The term didincms, de- 

 noting either § or J 9 without distinction, is in common use. 



