Fig. io8 Alaria esculenta. A, plant of A. oblonga with sporophylls. 

 B, sporangia and paraphyses ( x 200). C, germling sporophyte 

 ( X 100). D, female gametophyte ( x 80). (A, after Oltmanns; B-D, 



after Newton.) 



solid, unbranched stipe which is attached to the substrate by means 

 of small, branched rhizoids. It is naked below with an intercalary 

 growing zone that allows for continual renewal, whilst above the 

 growing region the stipe expands into a flattened rachis which bears 

 each year a fresh crop of marginal rows of sporophylls. The frond 

 finally terminates in an expanded sterile lamina with a well-marked 

 mid-rib, which is also an annual production. In addition to the 

 intercalary growth there is also a marginal growth that imparts a 

 wavy appearance to the terminal frond. This bears the so-called 

 cryptostomata, although these are barely more than tufts of hairs 

 arising in slight depressions. The sporangia are produced on the 

 lower blades mixed up with unicellular paraphyses. The gameto- 

 phytes are protonemal in form, simple or sparingly branched, the 

 male, as usual, being composed of smaller cells with terminal, 

 intercalary, or lateral antheridia, whilst the oogonia on the female 



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