PLATE LIX. 



1. VINCA ROSEA. 



MADAGASCAR PERIWINKLE. 



Tins genus comprehends plants of the shrubby, evergreen, up- 

 right, and traihng kinds. 



It belongs to the class and order Pentandria Monogynia, and 

 ranks in the natural order of Contorta. 



The characters are: that the calyx is a live- parted perianth, 

 erect, acute, permanent: the corolla one-pctalled, salver-shaped: 

 tube longer than the calyx, cylindric below, wider above, marked 

 with five lines, the mouth a pentagon: border horizontal, five-parted: 

 segments fastened to the apex of the tube, wider outwards and 

 obliquely truncate: the stamina have five filaments, very short, 

 inflexed and relrollexed: anthers membranaceous, obtuse, erect, 

 curved in, fariniferous on both sides at the edge: the pislillum has 

 two roundish germs, with two roundish little bodies lying b>» their 

 sides: style one common to both, cylindric, length of the stamens: 

 stigma capitate, concave, placed on a flat ring: the pericarpium has 

 two follicles, round, long, acuminate, erect, onc-valved, opening 

 longitudinally : the seeds numerous, oblong, cylindric, grooved, 

 naked. 



The species cidtivated are: 1. V. minor. Small Periwinkle; 2. V. 

 major. Great Periwinkle; 3. V. rosea. Madagascar Periwinkle. 



The first has a perennial creeping root, with branched fibres: 

 the Whole plant smooth and shining: the stems round, slender, 

 leafy, erect when in flower, irom nine inches to a foot in height, antl 

 much higher when .su])ported by bushes, marked on each side with 

 a groove faintly impressed; after flowering, prostrate, elongated, 



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