660 



BOTANY 



PART II 



year. The inflorescence sometimes bears sessile dichasia of 2-3 flowers in a 

 terminal spike ; in other cases by the development of brandies from the lower leaf- 

 axils it becomes a branched panicle. The single flowers have five stamens, and 

 are only slightly zygomorphic ; the three posterior stamens have hairy filaments, 

 and are further distinguished from the two anterior stamens by the transverse 

 position of their anthers. Scrophularia has a two-lipped corolla with a very short 

 lower lip, four stamens and one staminode. Digitalis, Foxglove (Figs. 706, 707), 

 has an obliquely campanulate corolla and four stamens. The flowers hang from 

 one side of the obliquely ascending raceme. The corolla in Linaria and Antirrhinniii 



hfff-^, 



Fig. 701. — Nicotiana tahacutn. a, Flower; b, corolla, cut open uud .sijread out flat ; c, ovary 

 (' and e, young fruit, (a, h, e, nat. size ; e, </, x 2.) 



is spurred. Gratiola with two fertile stamens and two staminodes. Veronica with 

 onl}' two fertile stamens. 



{h) Ilhinanthcae. — This grouji includes a number of closely related genera which 

 have adopted a more or less completely parasitic mode of life. Tlie most com- 

 pletely parasitic form is Lathraea, the species of which have no trace of chlorophyll ; 

 L. squamaria, the Tooth wort, is parasitic on the roots of the Hazel. Many [e.(j. 

 Tiir.da, Barlsia, Euplirasia, Odontites, Pedicularis, Melmtijnjrmn, Alectorolo'phus) 

 are semiparasitic. Although they possess green leaves they attach themselves 

 liy means of haustoria to the roots of other plants, from which they obtain 

 nutrient materials. Further details regarding the mode of life and develojiment 

 of these forms and the seasonal dimorphism they exhibit, will be found in the 

 literature cited C'). 



