XIV INTRODUCTION. 



64. The Corolla is usually of a thinner texture than the calyx, and variously 

 colored. Its leaves (Pttals), when of the same number as the sc|)als, always 

 alternate with tliem. They rn-c also often united by their contiguous mai-gins, to 

 fcrnn a vionopttaJous corolla. 



65. When the calyx and corolla are so nearly alike as not to be readily dis- 

 tinguished, they are collectively termed the Periunth. 



66. A flower is complete when all its parts are present ; incomplete, when the 

 floral envelopes, or a part of them, are wanting ; perfect, when the stamens and 

 pistils arc borne in the same flower ; imperfect, or diclinous, when they are borne 

 in separate flowers ; regular, when the sepals or jx:tals are of unifaim shape and 

 size; and irregular, when they are unlike in shape or size. 



67. Imperfect flowers are further distinguished into monacious, wlion those fur- 

 nished with stamens (slaminate or sterile flowers) and those furnished with pistils 

 {pistillate or fertile flowers) are borne on the same plant ; diacious, when they are 

 borne on separate plants ; and jiolygamous, when both perfect and imperfect flow- 

 ers are borne on the same or different individuals. 



68. The manner in which the parts of the floral envelopes are arranged with 

 respect to each other in the bud is termed their yEstivatiun. Tliey are vcdvcUe, 

 when their contiguous margins meet, without overlapping ; induplicate, when 

 these project inwardly ; reduplicate, when they project outwardly ; imbricated, 

 when the margins of one overlap the adjacent margins of the two next within ; 

 convolute, or twisted, when one edge of each piece covers the margin of the one 

 next before it, and tiie other edge is covered by the margin of the one next after 

 it; &nd plaited, when the parts are folded lengtiiwise. 



7. The Stamcus. 



69. A Stamen consists of a sac, called the Anther, and, usually, a stalk, called 

 the Filament, by which it is supported. 



70. They are Itypogipioiis, when they are inserted on the receptacle ; perigynous, 

 when on the calyx ; epigi/nous, when on the ovary ; epipetalous, when on the co- 

 rolk; and gynandrous, when they are united with the style. They arc, also, 

 often combined with each other, cither into one set (monadelphous), or into two, 

 three, or more sets {diadelphous, triadelphous, &c.). 



71. The Anther is composed, commonly, of two united cells, which open in 

 various ways, and discharge a yellow, fertilizing powder, culled the Pollen. The 

 part which connects the cells is the Connective. 



72. It is erect, or innate, when fixed by its base to the apex of the filament ; 

 adnale, when fixed to the filament liy its whole length; versatile, when fixed by 

 the middle to the apex of the filaments on wiiich it turns as on a pivot; introrsc, 

 when it faces inwardly toward the j)istils ; and extrorsc, when it faces outwardly 

 toward the petals. Occasionally, they arc united into a tube {syngemsioiis). 



73. lietwecn tiie stamens and the pistils is often a fleshy expansion, culled the 



DUk. 



6. The PUtilii. 



74. The I'istil.M occujiy the centre of the flower. They are iiiserle<l, singly or 

 in ft whorl, on the rccci)taclc ; or, when this is elongated or enlarged, they cover 

 its fnirfuco. 



