64 



FAMILIES OF FLOWERING PLANTS. 



a. 



i 



Fig. 53. — a. Biirwaiuiia biflora. h. Apteria 

 setacea. Plants natural size. Original. 



that of the ovary, or, as it is more generally expressed, the ovary is 

 inferior. The stamens are three or six, and the style is either simple 



or 3 -cleft. In the South they may 

 (^ be found in rich woods, growing 

 in moist decaying vegetable mat- 

 ter. Owing to the absence of 

 leaves it was for a long time sup- 

 posed that these plants were root- 

 parasites like the broom-rapes. 

 Figure 53 shows Burmannia hl- 

 fiora and Ajjterla setacea of natur- 

 al size; the former is distinguished 

 by having flowers with the peri- 

 anth conspicuously wing-mar- 

 gined. 



Family Orchidaceae. Orchid 

 Family. This large and most at- 

 tractive group includes the most 

 highly specialized of the monoco- 

 tyledonous plants. The carefully 

 conducted researches of Darwin and other scientists have demonstrated 

 that the marvelous complexity of floral structure exhibited by the 

 orchids is the result of special adap- 

 tation or modification to secure fer- 

 tilization through insect agency, and 

 often through the visits of some par- 

 ticular species of insect. 



Orchids are perennial herbs, 

 with great diversity of habit. It 

 may be stated as a general rule that 

 those growing in temperate climates 

 are terrestrial like most other plants, 

 while those that are natives of warm 

 or tropical regions are epiphytic, 

 like the Bromeliads which were dis- 

 cussed in a recent chapter (see sup- 

 plement, page 41). The roots of ter- 

 restrial species are usually thickened fk;. 54.— showy orchis (6'»c/H"««7^<'rt«/«/i*) 



1 , , ,. 11 showing parts of flower. (After Brittoq 



and tuberous, sometimes even bul- and Brown, in. F1. Northeastern u.s, 



