226 LJSSSOJftl WITS PLANTS 



have attributes that fit them for a wide or common range of 

 conditions. Generalized organisms are usually relatively simple, 

 or undifferentiated in structure the one from the other; they are 

 conceived to be fundamental or stem types, from which specialized 

 ascendants may arise in the long courses of time. The orchids 

 are highly specialized plants. 



258c. The environment is the sum of all the conditions or cir- 

 cumstances in which a plant or an animal lives. Literally, it means 

 the surroundings. The climate, soil, elevation and the like comprise 

 the environment. 



Suggestions. — Inasmuch as orchids are local or rare in most 

 parts of the country, the pupil may be obliged to resort to the 

 florist for specimens, although cypripediums are frequent in many 

 places. The larger greenhouse establishments usually grow such 

 orchids as East Indian cypripediums, lycaste, phalaenopsis, eattleya 

 and calanthe. 



XLII. PARTICULAR TYPES OF FLOWERS, 

 CONTINUED. (GRASS -LIKE PLANTS) 



259. Portions of the common buUrush, which 

 grows in clumps in low grounds, are shown in 

 Fig. 216. The panicled inflorescence is at a, and 

 an enlarged 'flower at b. The perianth is com- 

 posed of six pointed greenish sepals. (The pupil 

 should determine the significance of the scales 

 which are shown beneath the perianth in the pic- 

 ture.) The stamens are three, and stand against 

 the outer sepals. The pistil is 3-loculed, with 

 three feather-like styles. The flower is, therefore, 

 regular and simple in structure, and this suggests 

 that it is not highly specialized. 



