98 



A. H. Graves, 



ft--"-- 



In all other respects, however — internal structure, axillary scales, 

 &c. — the subtioral leaves are identical with the ordinary foliage 

 leaves. 



Koch and Irmisch have 

 called these two leaves 

 " folia floralia," an un- 

 wieldy term, whose Eng- 

 lish equivalent is at present 

 applied to the modified 

 leaves forming the floral 

 envelope in the Phanero- 

 gams. On account of their 

 position near the pe- 

 duncle and their slight 

 modification in form, they 

 approach the category of 

 " bracteal leaves " or 

 •' Hochblatter " of Stras- 

 burger (1908, p. 31) and 

 Goebel (1898, p. 578), yet 

 the difference from the ordinary leaves is so slight that such a classi- 

 fication seems unwarrantable. I have therefore adopted the term 

 " subfloral leaves," although bearing in mind their approach to typical 

 bracts. 



E. Scale Leaves 



Figui'e 18. — Sketch of flowering branch, show- 

 ing location of flowers and subfloral leaves. 

 I natural size. 



Besides the subfloral leaves and ordinary foliage leaves, two other 

 sorts of leaf structures occur in Ruppia maritima, quite similar in 

 appearance and structure. These are very small membranous for- 

 mations — one kind borne at the base of the ordinary branches and 

 the other at the base of the floral axis (PL I, fig. 1 ; PI. II, fig. 6, 

 vsl; Text-figs. 19—20, vsl and fsl). The first sort is plainly what 

 Goebel (1898, p. 572) has in mind when he writes of " Vorblatter." 

 He says, " Die Vorblatter sind zunachst charakterisiert durch ihre 

 Stellung. Wir finden sie — wo sie uberhaupt vorkommen — bei den 

 Dikotylen meist in Zweizahl an der Basis der Seitensprosse, bei den 

 Monokotylen wird gewohnlich ein Vorblatt angenommen, welches auf 

 der dem Mutterspross zugekehrten Seite des Tochtersprosses steht." 



Strasburger (1908, p. 429) also mentions "Vorblatter," but with 

 him they signify bracts or bracteal leaves. It is his category 

 " Niederblatter " or " scale leaves " that includes the structures 

 described by Goebel as " Vorblatter." 



