168 



Transactions. 



Leaves dull green, fleshy, with fleshy petioles ; leaf 1-2 in. long, including 

 the petioles, which are longer than the blade ; |- T % in. broad ; petioles 

 sheathing at the base, and hairy ; leaves broadly ovate, margins crenate ; 

 large veins prominent on under-surface. 



Fruit conspicuous. Peduncles elongated, often 3 in. long or more, pro- 

 jecting above the foliage, with raceme of fleshy orange-coloured drupes, 

 pendulous, J-J in. long. 



(c.) Anatomy. Fig. 4. 



Epidermis : On both surfaces cells large, walls thin, outline wavy in 

 surface view, no cuticle ; stomata frequent, prominent, wide open, guard- 

 cells containing numerous chloroplasts. 



Chlorenchyma differentiated : on upper side two layers of palisade 

 cells, the rest of the chlorenchyma consisting of large rounded cells ; air- 

 spaces beneath stomata. Embedded in the chlorenchyma were seen large 

 round cells containing sphaerocrystals. 



xy iph^ /oner ep. 



air 



pal .sphaero rrysfa/ 



Fig. 4. — Ghinnera armaria : Part of T.S. of leaf. 



Fibro-vascidar bundles : Small patch of phloem towards underside, 

 beneath a patch of xylem ; bundle surrounded by sheath of large round 

 colourless cells. 



When the stem is cut through, two or three blackish specks on the cut 

 ends can be seen by the naked eye. On microscopical examination these 

 are seen to be caused by the presence in the outer cortex of colonies of 

 Nostoc. 



(d.) Conclusion. 



The habit and the fleshy reduced stem of Gunnera arenaria are xero- 

 phytic ; but the leaf, with its prominent wide-open stomata on both 

 surfaces, large rounded chlorenchyma cells, large chloroplasts, and well- 

 marked sponge parenchyma, is strongly mesophytic, in accordance with the 

 moist habitat. 



This plant, pot-grown in the greenhouse, throve both when watered 

 regularly and when kept dry. 



