Manchester Memoirs, Vo/. xlvii. (1902), No. *X, 5 



Both kinds of flowers are found in little heads or 

 buttons, which are borne on erect spikes at the termina- 

 tions of the branches, and the whole plant has an aromatic 

 odour like that of wormwood, and from its external 

 resemblance thereto it derives its specific name. The 

 separate flowers are tubular, there being from a dozen to 

 sixteen male flowers in each little head ; and, generally 

 below them, little verticils separated by bracts, each 

 verticil containing about three or four female flowers ; 

 sometimes the spikes contain pistilliferous flowers only. 

 The male flowers have a corolla, but no calyx ; their 

 anthers are conspicuous in the throat of the corolla, and 

 they contain an abundance of nearly spherical pollen 

 grains bearing very short spines over their surface ; an 

 abortive pistil, consisting only of its style, rises from the 

 centre of the five anthers of each flower. The female 

 flowers have a calyx, but no corolla, and their most 

 conspicuous feature is the protruding halves of their bifid 

 style, which curve over as far down as the base of the 

 pistil while the stigma is fresh, but after fertilisation they 

 curl up into the shape of a bishop's crozier. 



As a rule the St. Anne's plants show a tendency to 

 produce antheriferous flowers only, but occasional patches 

 occur in which all the flowers of the spike are pistilli- 

 ferous, no staminiferous flowers occurring upon them ; 

 the accompan)'ing Plate i is photographed from a sheet 

 of herbarium specimens in which the free portions of 

 the spikes contain staminiferous flowers with very few 

 pistilliferous flowers below ; while Plate 2 represents two 

 similar examples of plants upon which there are no 

 staminiferous flowers— these pistilliferous spikes forming 

 less than one per cent, of the whole. 



Ambrosia artemisiafolia grows at St. Anne's in patches 

 several yards in diameter, and it monopolises the rough 



