DIMORPHIC CARPELLATE FLOWER OF 

 ACALYPHA INDICA, L. 



BY 



L. A. Kenoyer, 



Agricultural Institute, Allahabad. 



Acalypha indica L. is a common member of the Euphorbiacese 

 growing over most of India as a weed on waste ground. It is said by 

 Hooker to grow over a wide tropical area, from the Philippines to 

 Tropical Africa. 



The flowers are apparently in spikes ; but a closer examination 

 shows that the flower cluster is in reality a racemose cyme, each of 

 the branches from the main axis being a cyme of three or more 

 flowers. The lower branches, which are almost concealed by large 

 bracts, bear trilocular carpellate flowers closely resembling in struc- 

 ture the carpellate flowers of Bicinus and the Euphorbiacese in gene- 

 ral. Higher on the axis and with much smaller bracts are cymes of 

 staminate flowers, while at the very tip without a bract is a peculiar 

 bilaterally symmetrical unilocular carpellate flower which bears a 

 single seed. This flower has three or four sepals which vary con- 

 siderably in their position, and a monocarpellary pistil. The ovary is 

 a transverse cylinder slightly depressed at either end and resembling 

 a muff in appearance. The attachment of the stalk and sepals is to 

 the curved surface midway between the ciliate-bordered ends. Arising 

 from this point of attachment is the style. It resembles the style of 

 a single carpel of the trilocular pistil except for its basal position and 

 the fact that it is more fimbriate, having six to eight thread-like 

 branches instead of three to five. 



As the flower develops into the fruit the upper part of the cylin- 

 der elongates so that in its front or rear aspect the fruit is triangular 

 with its apex downward. The edges are extended as hollow auricles 

 which are fringed and rugose. The whole appears like a rhombic leaf 

 bent so that the tip touches the base and enclosing a seed at 

 its center. 



To determine the significance of this terminal flower, inflores- 

 cence tips of various ages were killed in chrom-acetic acid, imbedded 

 in paraffin, and sectioned. It was found that this flower starts as a 



