A case of apogamy with Dasylirion 

 acrotriclium Zuee. 



BY 



F. A. F. C. WENT and A. H. BLAAUW 



with Plate V. 



In the summer of 1904 a spécimen of Dasylirion acrotri- 

 chum Zucc. was in bloom in the Utrecht Botanical Garden. 

 The home of this tree-like Liliacea is in Mexico ; on a short 

 stem it bears a bundle of flat leaves wit thorny margins. 

 Although the plant is pretty often cultivated in European 

 botanical gardens it is very seldom seen in bloom. Hence 

 constant attention was paid to the hère mentioned spécimen. 

 The inflorescence was two mètres long ; the principal axis 

 was ramified and had a great number of steeply erected 

 latéral axes in the axils of bracts; each of thèse carried 

 some 50 to 150 unstalked female flowers. Dasylirion is 

 dioecious so that maie flowers were entirely absent. 



Each flower had a perianth consisting of six green leaflets 

 and a pistil; this latter consisted of a triangular ovary 

 with a short style and three stigmas. The ovary was 

 unilocular and had on its bottom three ovules. 



After the flowers had finished blooming it seemed as if 

 some ovaries began to swell. As there could be no question 

 of fertilisation in the absence of maie sexual organs it 

 was thought that perhaps a new case of apogamy orpar- 

 thenogenesis was présent hère. The ovaries were now 

 regularly examined; they more and more assumed the 



