LESSONS IN BOTANY. 225 



The tapering, divergent styles, stigmatic along the inner sur- 

 face, unite below forming a compound ovary. Study the style, 

 noting its form, size, etc., find also the vascular bundles. Make 

 a cross section of the ovary and notice the form and position of 

 the ovules, especially notice the placenta on which they stand and 

 find out how it is formed. The fleshy pod incloses the seeds. 

 Where the ripe seed breaks away from the stalk a scar called the 

 hilum is formed. A cross section of a seed shows the thin brown 

 coat or testa, and the food material making up the main body 

 of the seed. 



In these plants we have for the first time a complete flower. 

 The calyx and corolla serving in the bud and blossom as organs 

 of protection for the reproductive organs; the corolla in addition 

 serves to attract the attention of insects and birds, whose visits 

 are often beneficial to plants. Sometimes the calyx also becomes 

 colored and attractive. And here first we find the typical closed 

 ovary, the distinguishing characteristic of the Angiospermae. In 

 the oat the ovule and seed are adherent to the ovary, while in 

 trillium they are distinct. The trillium represents the lily 

 family very well except in the veining of the foliage leaves and 

 the color of the sepals. 



Among the useful plants of this order may be mentioned as- 

 paragus and the onion, used for food; the aloe, green hellebore, 

 colchicum, sarsaparilla and others are used in medicine; and a 

 large number of lilies are cultivated as ornamental plants. 



The Palm Family belongs to the monocotyledons, and for eco- 

 nomic value is second only to the grass family. The members of 

 this family furnish enormous quantities of food materials, of, 

 material for house-building, and for an endless variety of house- 

 hold goods and utensils. But nearly all the useful members of 

 the family are natives of the tropical regions. 



The Orchid Family is an interesting member of this group of 

 plants. They are terrestrial plants in some cases, but generally 

 they are air plants, growing most abundantly and in greatest 

 variety in the tropical regions. They all have irregular flowers, 

 often having most grotesque forms, and sometimes simulating 



L. S. 15 



