28 



Transactions. 



from that of R. subsericea in the amount of tomentum apparent in a trans- 

 verse section. Fig. 8 represents diagrammatically the relative area taken 



up by the hairs in the terminal bud, 

 there being about four times as much 

 tomentum in the terminal bud of R. 

 subsericea. 



A cross-section of a leaf shows the 

 following structure (fig. 9) : Epidermis, 

 very regular cells ; cuticle rather thin ; 

 stomata level with cuticle and found 

 on both surfaces. The cells are elongated 

 in the direction of the long axis of the 

 leaf. Hairs as in R. tenuicaulis, arising 

 from distal end of epidermal cell and 

 leaning forward towards leaf-apex. At 

 the leaf-base the lateral Walls of the epi- 

 dermal cells are straight, but become 

 wavy towards leaf -tip. There is very 

 little production of anthocyan in the epi- 

 dermal cells. Chlorenchvma continuous 

 round periphery of leaf. On the upper 

 surface there are about three layers of cylindric or elliptical cells. On 

 the lower surface there is a single layer of spheroidal cells. Water-tissue, 



c. e. * 



Fig. 8. — Diagram of transverse sec- 

 tion of rosette of Raoulia glabra. 



0. E. F. del. 



Fig. 9. — Transverse section of leaf of Raoulia glabra. 



a central tissue from one to three layers deep of large clear polygonal or 

 spheroidal cells with scanty chlorophyll. 



(c.) Root. — Fine and wiry ; not so deeply penetrating as in other species. 



(d.) Flower and Fruit. — The flower-heads are very large in comparison 

 with the other raoulias. They are 6 mm. or 7 mm. long, and about 6 mm. 

 in diameter. The involucral bracts are in three or four series. The florets 

 are very numerous, varying from thirty to fifty. Female florets occupy 

 the periphery, and are rather less in number than the hermaphrodite ones. 

 The cypsela is oblong, slightly hairy, and crowned with a dense tuft of soft 

 pappus-hairs. 



