GAMOPETAL^— LABIATE 



iSS 



and the other four stamens alternate with the petals (see 

 diagram). The anthers are in pairs close together under the 

 arching upper lip of the corolla : they have peculiar diverging 

 anther-lobes. Carpels two, syncarpous, superior. The ovary 

 (pv) is four-lobed and divided into four chambers, each with 

 one ovule (<?). The style is attached to the ovary at the base 

 of the junctions of the four lobes : it l(Sy) is single, but forks 

 above and is capped by two stigmas. The two stigmas 

 indicate that only two carpels are represented in the gynsecium. 

 Thus the ovary should be two- 

 chambered, but each chamber is 

 further divided into two halves by 

 a false septum. The two stigmas 

 are median in position, thus indi- 

 cating the two carpels are median. 

 Nectary (n) a fleshy hypogynous 

 outgrowth of the receptacle lying 

 at the anterior face of the ovary. 

 Fruit. — Each chamber of the 

 ovary becomes a one-seeded in- 

 dehiscent nut-like body (nutlet). 

 The fruit may be described as 

 a peculiar schizocarp. Pollina- 

 tion. — We note — (i.) The flowers 

 are not erect but point obliquely upwards, and are median- 

 zygomorphic. (ii.) The upper lip protects the pollen and 

 honey from rain. (iii.) The honey is deeply placed and 

 concealed ; it collects at the bottom of the corolla-tube. 

 A ring of hairs in the latter acts as a rampart to protect 

 the honey from marauding insects which would not effect 

 cross-pollination, (iv.) The flower is specially adapted for 

 cross-pollination by the agency of humble-bees. The humble- 

 bee alights on the middle lobe of the lower lip, pushesits head 

 down the tube in order to reach the honey which is at the 

 anterior face of the ovary. The back of the bee thus comes 

 into contact, 'first with the anterior stigma, and immediately 

 afterwards with the anthers. The consequence is, that pollen 

 lodged on the bee's back by a previously visited flower is 

 conveyed to the stigma of a flower before the pollen of this 

 latter is touched by the humble-bee; and cross-pollination 

 results. We note how perfectly the humble-bee fits into 



Fig. 192. — Floral diagram of 

 Dead Nettle. 



