NUCULIFERj;. 



531 



the leaves are opposite on a stem with well-developed internodes, 

 and the inflorescences are borne in their axils. The order also 

 presents a transition from insect-pollinated to wind-pollinated 

 flowers. The flowers are protogynous, wind-pollinated in P. major and P. 

 lanceolata, partly also in the other species, but insect-pollination also occurs, 

 and P. media has three kinds of flowers, some of which are adapted for wind- 

 pollination (Fig. 571), others, with short filaments, for insects. Littorella 

 lacustris (Shore- weed) is the most reduced of the Plantaginaceas : an 

 aquatic plant with rosettes of round, awl-like leaves and diclinous 

 (monoecious) flowers. In the axils of the foliage-leaves is a very short 

 3-flowered spike, formed by 2 sessile $ -flowers, and above them a long- stalked 

 $ -flower ; all the flowers are lateral, the terminal one being absent, as in 

 Plantar/o. The c? -flower is essentially the same as in Plantar/a, but the $ -flower 

 has a scarious corolla, with a narrow, 3-4-deutate mouth, which closes tightly 

 round the nut-like fruit. 



570. 571. 



FIGS. 570, 571. Plantago media. 



FIG. 570. Diagram of Plantago media. 



FIG. 571. Two different forms of the flower (magnified): 1, chiefly adapted for pollina- 

 tion by wind; 2, fjr insect-pollination, a The stigma; b the calyx: fc the corolla. 



The genus Plantago constitutes nearly the entire order (200 species). Some 

 are widely distributed weeds (e.g. P. major, " The white man's footstep"). In 

 P. psyllium (S. Eur.) the integument of the seeds is mucilaginous, and swells 

 considerably in water. 



Family 31. Nuculiferse. 



The flowers are liypogynous and zygomorphic (in Boraginacete 

 and Cordiacece, however, they are regular, except Echium and An- 

 chusa arvensis). The calyx is gamosepalous, the corolla bilabiate 

 (except in the two orders mentioned), mostly after |, i.e. divided 

 into a 2-leaved posterior portion, and a 3-leaved anterior portion. 



