MARINE ALGJil. 3 



2. Lessonia grandifolia. 

 (Plates I. and II , figs. 5-9.) 

 Lessonia grandifolia, Gepp, Journal of Botany, 190.5, p. 105. 



Callus radicalis dense et irregular! ter ramosus, coriaceus. Stipes valde com- 

 pressus, marginibus obtusis, bis vel ter vel quater dichotomus, subter quamque 

 dichotomiam complanate expansus ; rami sectione transversali plano-convexi ancipites 

 marginibus acutis, laxe torti. Stipes totus e callo usque ad laminas 30-120 cm. 

 Laminae lanceolato-lineares longissimae (1-8 met.), latse (8-45 cm.), marginibus grosse 

 undulatis integerrimis, apice deleto, fissiles, in statu sicco coriacese sed fragiles. 

 Stipitis substantia lacunis annulisque carens. Laminae substantia coriacea e stratis 

 tribus composita ; cellulis corticalibus minutis fuscis congestis in series verticales 

 breves dispositis ; subcorticalibus rotundatis 1-2 — seriatis quam corticalibus 

 magnitudine duplo majoribus ; hyphis medullaribus hyalinis extrorsum dense introrsum 

 laxe invicem juxtapositis flexuosis tubulos multos subinfundibuliformes vagin^ e cellulis 

 parvulis composite vestitos circumstantibus. Zoosporangia ignota. Figs. 1-9. 



Cape Adare (Jan. 9, 1902), hauled up with anchor from 18 fathoms; Coulman 

 Island, off Cape Wadsworth, 18 fathoms. 



In our previous account of this species (Journal of Botany, I.e.) we quoted 

 specimens gathered both by the Scottish and the British Expeditions, and from' the 

 order in which they were cited it would naturally be inferred that the type described 

 was the ' Scotia ' plant. We wish to state that the type was and is the ' Discovery ' 

 plant, and that the diagnosis was founded upon it alone, the ' Scotia ' material being 

 too fragmentary to furnish data for a complete description. Though at the time we 

 regarded the ' Scotia ' fragments as belonging to L. grandifolia, we are now convinced, 

 after having examined more carefully their microscopic structure, that the ' Scotia ' 

 and ' Discovery ' plants must be distinguished specifically. We therefore describe 

 them both in detail. 



L. grandifolia is one of the larger species of Lessonia, but is not one of the 

 dendroid members of the genus, that is, it has not the sturdy, round, tough, persistent, 

 well-developed stem, apically branched, and showing rings of secondary thickening, 

 which is so marked a feature of L. fuscescens and L. nigrescens. In L. grandifolia the 

 stem is subsidiary to the laminae, and the species is distinguished from all the rest of 

 the genus by the great size of its unsplit laminae ; the largest laminae previously 

 recorded for any of the species were 60-90 cm. in length, and occurred in L. fuscescens, 

 Bory (Hooker, Flora Antarctica, I. 1847, p. 458). 



In our specimens of L. grajidifolia the largest lamina is 5 •7 m. when dry, 

 and, when first taken out of the formalin solution in which it was preserved, measured 

 7*3 m. in length by 45 cm. in width. Another lamina measured 4*5 m. by 35 cm. 

 wide when moist before desiccation. None of the mature fronds arc complete at the 

 apex, but we are unable to say whether or not this means that the previous year's 



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