FLORA OF BERMUDA 



All plants may be grouped in four main categories, known as 

 Phyla or Subkingdoms, as follows: 



Phylum 1. Spermatophyta, those which bear seeds, a seed 

 being different from all other vegetable structures by containing an 

 embryonic plantlet. All spermatophytes bear flowers of one kind or 

 another, and this phylum is also called Anthophyta, or flowering 

 plants and, to distinguish it from the three other phyla collectively, 

 Phanerogamia. Phyla 2, 3 and 4 taken together are called Crypto- 

 gamia ; all these are seedless. 



Phylum 2. Pteridophyta, comprises ferns and fern allies; all 

 are flowerless and have two separate and distinct alternating genera- 

 tions, the one represented by the fully developed plant having root, 

 stem and leaves, with vascular tissue and bearing spores, a spore 

 being a single vegetable cell capable of growing into a new plant; 

 the other, called the prothallium stage, is small, inconspicuous, 

 grows from the spores, has no vascular tissue, is not differentiated 

 into root, stem and leaves, and bears the sexual organs; from the 

 female organ of the prothallium (archegonium) the fully developed 

 spore-bearing plant again arises ; the male organ, borne either on the 

 same prothallium or on a different one, is called an antheridium. 



Phylum 3. Bryophyta, consists of mosses and their allies; all 

 are small flowerless plants with alternating sexual and non-sexual 

 (spore-bearing) generations, but the spore-bearing generation never 

 becomes separated and independent; the sexual generation is com- 

 monly the more conspicuous and is, in most cases, differentiated into 

 stem and leaves, while the spore-bearing generation is never thus 

 differentiated; their spores are borne in conceptacles termed cap- 

 sules, and from the spores the plant again develops. Bryophytes 

 consist almost wholly of cellular or non-vascular tissue. 



Phylum 4. Thallophyta, includes the algae, fungi and lichens ; 

 all are flowerless and their methods of reproducing and propagation 

 are varied. They contain no vascular tissue (except a few large 

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