M.WICHURA ON THE WINDING OF LEAVES. 293 



see 44 ; for Sisyrinchium anceps, 53. The petals of the spe- 

 cies of Iris are constantly wound to the left in the contorted 

 aestivation. Aristea cyanea, Ait. ; A. bracteata, Pers. ; A. ca- 

 pitata, Gawl. ; A. carulea, Vahl ; A. spiralis, Vahl : petals wind- 

 ing to the left as the flowers wither. The withering flowers of 

 Iris exhibit the same twistings, apparently however without de- 

 finite direction. 



71. 



Amaryllidece. Hitherto I have only met with left-wound 

 stem-leaves in this family. The species examined were : Leu- 

 cojum (pstivum, L. ; Sternbergia colchiciflora, W. K. ; Brunsvi- 

 gla Josephines, Ker. ; a Cyrtanthus, the leaf of which is repre- 

 sented in fig. 8 ; Zephyr anthes Candida, Herb., several species 

 of Narcissus, Gethyllis and Alstrcemeria. For the doubly- 

 wound stem-leaves of Alstrcemeria pelegrina, see 43. Narcis- 

 sus moschatus, L. : petals right soon after the flower opens. 

 Pancratium patens. Red. ; P. expansum, W. Herb. ; P. lobatum, 

 Kl. : dehiscing anthers right. 



72. 



Bromeliacece. See 4? and 42, for the winding of the 

 outer and inner perianth in the bud, and of the leaves of the inner 

 perigone after the flower is open. We also observe a constant 

 winding towards the left in the style. 



73. 



Orchidea. Epidendrum macrochilum, Hook.; Scaphy glottis 

 violacea, Cyrtochilum flavescens, Diuris filifolia, Lindl. : stem- 

 leaves left. Ornithidium album. Hook. ; Cymbidium giganteum ; 

 Disa Zeyheri, Sond. ; D. tenella, Sw. : stern-leaves right. For 

 Dichaa squarrosa, Lindl., see 45. Epidendrum cochleatum, 

 L. ; Trichopilia tortilis, Lindl. : perigonial leaflets left, with the 

 exception of the labellum which does not wind. Orchis hircina, 

 Scop. : lobes of the labellum, especially the long middle lobes, 

 left. Cypripedium Calceolus, L. : the pair of corresponding 

 segments of the outer perigone right. Every one is aware of 

 the half revolution of the germen of many Orchideae, by which 

 the position of the parts of the flower in relation to the axis of 



