DISAPPEARANCE OF PARTS. 189 



b}- a short dotted line) is vacant, this petal being suppressed, 

 thereb}^ rendering the blossom un symmetrical. In Aconite 

 (Fig. 357-359), the plan of the blossom is the same, 

 but the uppermost and largest of the five dissimilar 

 sepals forms a helmet-shaped or hood-like body ; 

 three of the petals are wanting altogether (their 

 places are shown by the dotted lines in the ground- 

 plan, Fig. 359) ; and the two upper ones, which ex- 

 tend under the hood, are so reduced in size and so 

 anomalous in shape that the}^ would not be recog- 

 nized as petals. One of these, enlarged, is exhibited 

 in Fig. 360. Petals and other parts of this and of va- 

 rious extraordinaiy forms were termed b}' Linnaeus 

 NECTARIES, a somewhat misleading name, as they 

 are no more devoted to the secretion of nectar than 

 ordinary petals or other parts are. In these flowers, 

 moreover, the stamens are much increased in number. 



345. Analogous abortion of some of the stamens, along with 

 a particular iiregalaritj' of the perianth, especially of the corolla, 

 characterizes a series of natural orders with coalescent petals. 1 

 These flowers are all on the 5-merous plan (except that the 

 gynoecium is 2-merous), but with corolla, and not rarely the 

 calyx, irregular through unequal union in what is called the bila- 

 biate or two-lipped manner. The greater union is always median, 

 or anterior and posterior, and two of the coalescent members form 

 one lip, three the other. The two posterior petals form the 

 upper lip, the anterior and two lateral form the lower lip of the 

 corolla ; in the calyx, when that is bilabiate, this is of course 

 reversed. In some, as in Sage and Snapdragon, the bilabiation 

 of the corolla is striking (Fig. 479-481), and readily comparable 

 to the two jaws of an animal ; in others, the parts are almost regu- 

 lar. The suppression referred to is, in most of these cases, that 

 of the posterior of the five stamens, as in Fig. B61, where it is 

 complete. In Pentstemon (Fig. 362), a sterile filament regu- 

 larly occupies the place of the missing stamen. The position 

 sufficiently indicates its nature. This is also revealed by the 

 rare occurrence of an imperfect or of a perfect anther on this 



1 These natural orders in which this occurs, or tends to occur, are the 

 Serophulariacea3 (Snapdragon, Pentstemon, Mimulus, c.), Orobanchaceie 

 (Beech-drops), Lentibulacese (Bladderwort), Gesneraceae (Gloxinia), Big- 

 noniaceae (Trumpet Creeper, Catalpa), Pedaliacese (Martynia), Acanthacese, 

 Labiatae (Salvia, Stachys), c. 



FIG 360 A petal (nectary) of an Aconite, much enlarged. 



