90 



disc. Many plants in this family do not 

 have the striking ray flowers. But all the 

 plants in the composite family bear many 

 small flowers in one head so closely 

 grouped that the head looks like a single 

 blossom. 



There is almost no end to the species 

 of composites. Some may grow on rub- 

 bish heaps and in uncared-for city lots. 

 Here you will find the burdock, w^hich 

 children often call "stickers," and the 

 cocklebur with its vicious burs. Along 

 the roadside grows the ragweed respon- 

 sible for hay fever: and where the grround 

 is damp, the wild lettuce. In the vege- 

 table garden you will find the artichoke, 

 oyster plant, lettuce, and chicory. These 

 are all composites. It is by far the largest 

 family among flowering plants. 



Now the class might sum up the pages 

 on angiosperms by doing Exercise io. 



In the last problem vou examined the 

 complex animals first and you ended 

 with the simplest forms. In this problem 

 you began with the simplest fonns and 

 ended with the most complex. "\'ou 

 learned about algae, simple water plants 

 that never bloom and that have no root 

 or stem or leaf. You learned about many 

 simple plants that were not even green and 



The Living Things of the Earth unit i 



often did not grow in soil. These were the 

 fungi, the microscopic plants like bac- 

 teria and yeasts, the many molds, and 

 the much larger mushrooms. Later you 

 studied the more complex mosses and 

 then the larger ferns. You found that the 

 ferns have leaves and stems and roots 

 but bear neither blossoms nor seeds nor 

 fruit. 



Finally you studied two large groups 

 of plants that looked like plants. First 

 you looked at the evergreens that bear 

 cones and then at the real flowering 

 plants. You learned something of mono- 

 cots, the grasses, orchids, lilies, and palms, 

 and of the dicots, which are used in so 

 many ways. There were tall trees and 

 tiny herbs. At first glance these seemed 

 to differ much among themselves but all 

 of them had a root, stem, and leaves; all 

 bore blossoms or cones, and all produced 

 seeds. 



In this study you met plants you had 

 not seen before. You were assisted in 

 learning their names by gathering them 

 into groups or classifying them. In the 

 next problem you will read how, many 

 years ago, a scheme was devised for 

 naming and classifying the many living 

 things of this earth. 



Summary 



This simplified tabic will help you review the plant kingdom. 



PHYLUM 1. Thallophytes (Thallophyta): Plants without flowers and fruit. Also 

 lacking root, stem, and leaf. 

 SUBPF^'S'I.UM I. Algae: Simple thallophytes with green coloring matter. With 



few exceptions, acjuatic. Green, hrown, and red seaweeds and other plants. 

 SUBPin'LUAl II. I'ungi: Simple thallophytes lacking green coloring matter. The 

 grouji inchnles mushrooms, molds, yeasts and bacteria. 

 PHYLUM II. Hryophytes (Bryophyta) : Plants without flowers and fruit. Green 

 Mostl)' with simj)le stems and roothke and leaflike parts. Small and incon- 

 spicuous. 



