AEEANGEMENT OF APPENDICULAR OEGANS. 77 



the torus are glandular, and usually secrete honeyed fluids, whence they have been 

 classed with nectaries^ of which we are about to speak. 



Nectaries or nectariferous glands are usually developed from the torus, and placed 

 upon it or the organs developed from it. 



The receptacle of the Radish (fig, 453), Wallflower (fig. 10), and othet Oruciferce, 

 bears four or six glands ; — the Periwinkle (fig. 454) two ; — Sedum (fig. 455) five ; — 

 most GesneriaceoB also five ; but in this Order all intermediates between five free 

 glands and a large hypogynous or epigynous disk are to be found. In the BtroAJu- 

 berry (fig. 401), Peach (fig. 368), and other Rosacece, the orange-yellow layer of the 

 torus, which is spread over the calyx, secretes superficially a honeyed liquor ; but 

 often for so short a time that it is difficult to observe it. In Ranunculus (fig. 237) a 

 small nectary occurs, protected by a scale, at the base of the claw of each petal. In 

 Berberis (fig. 238), each petal bears, a little above the base, two"^ naked ovoid necta- 

 ries. In the Fritillary (fig. 456), the six petaloid perianth-segments each bear a 

 nectary a little above the base, which, instead of projecting, forms a furrow. In the 

 Lily, a double nectariferous furrow extends along the face of the midrib of each 

 petal. In Parnassia (fig. 457), opposite each petal there is a petaloid scale which 

 ramifies into three, five, seven, nine, or fifteen branches, each tipped by a globular 

 nectary. 



Nectaries are sometimes on the tip or base of the connective of the stamens, as 

 in Adenanthera, Prosopis, &c. In Hea/rtsease (fig. 458), two nectaries pro^ 

 ceed from two of the stamens, and, projecting from the connective at the 

 base of the anther, form two recurved tails, sheathed in the hollow horn 

 of the lower petal, at the base of which they secrete a sweet liquor from 

 their tips. 



It has already been remarked that hollow petals contain a nectary in 

 their cavity {Columbine, fig. 246 ; Aeondte, fig. 247 ; Nigella, fig. 244; Helle- ^'"'^^a' 

 . bore, fig. 243; Winter Aconite, fig. 244 bis). and androBcium. 



In monopetalous corollas the nectaries maybe superficial {Honeysuckle, Lilac) , or 

 occupy a cavity which externally forms a boss or spur {Linaria, fig. 286 ; Snap- 

 dragon, fig. 285; Gentranthus, fig. 291) ; in the latter case the corolla is irregular, 

 and the stamens are often imperfect ; but it is difficult to say whether the necta- 

 ries are the cause or effect of this irregularity. 



Nectaries are not confined to the torus ; they are found on the external surface 

 of the calyx in Malpighiacece; and a glandular secreting layer occurs in the thick- 

 ness of the septa of the ovary of Liliaceoe, named by Brongniart ' glandes septales.' 

 In unisexual flowers, it often happens that the absent organs are.'^replaced by necta- 

 ries {Melon, and many other diclinous plants). 



ARRANGEMENT OF APPENDICULAR ORGANS AROUND THE AXIS. 



Appendages or appendicular organs are lateral developments from the vegetable 

 axis : — the leaves, bracts, sepals, petals, stamens, and carpels. 



It has been stated (Introd. p. 2), that leaves are either opposite, whorled, or 



458. Heartsenae. 



