MR. G. BENTHAM'S BOTANICAL MEMORANDA. 73 



Botanical Memoranda. By George Bentham, Esq., Y.I'.L.S. 

 [Read May 3rd, 18G0.] 



1. Involucre of Anemone. 



The so-called involucre of Anemone is generally described as con- 

 sisting of three, or in some instances more (as in Pranthis), ver- 

 ticillate leaves, — an arrangement perfectly anomalous in a group 

 where the leaves are essentially alternate. On carefully examin- 

 ing, however, its insertion in the several species, and comparing it, 

 on the one hand with the floral leaves of some species of Hellcbo- 

 rus, Nigella, &c, and on the other hand with the radical or other 

 leaves of the same species, it will be found that it is usually more 

 or less unilateral, and that it may be considered in fact as a single 

 amplexicaul leaf, divided to the base into three or more distinct 

 segments. 



2. Stigmas o/Tapaveracea?. 



There is much confusion in the characters occasionally given to 

 some genera of Papaveracece in the description of the relation of 

 the stigmas to the placentas, opposite to, or alternating with them. 

 Brown and others have, however, long since pointed out that, as 

 parietal placentas proceed normally from the margins of the car- 

 pellary leaves, the stigmatic summits, being central, must neces- 

 sarily alternate with them ; and that when, as in Cruciferce, the 

 stigmatic lobes are immediately over the placentas, each lobe con- 

 sists of two united moieties of two adjoining stigmas. The manner 

 in which this is effected, and the regular gradation from the alterna- 

 tion to the opposition of the stigmatic lobes and placentas, are beau- 

 tifully shown in Papaveracece. 



In the tribe of Bomneyece, consisting of Platystemon, Platystig- 

 ma (including Meconella) and Momneya, as also in Hypecoum, the 

 stigmas or stigmatic summits of the several carpels remain perfectly 

 distinct and more or less diverging, necessarily, therefore, alter- 

 nating with the placentas, and showing a first approach to the 

 apocarpous structure exemplified in Panunculacece. 



In all other Papaveracece the stigmas (or stigmatic surfaces) of 

 the several carpels are confluent on the extremity of the more or 

 less lobed style, or even the summits of the carpellary leaves are 

 completely united into an entire style, the stigmatic extremity of 

 which forms a clavate, globular, conical or flattened mass, on the 

 surface of which the stigmas form broad radiating or undulating 

 1 iues. The gradation may be traced through the follow in g genera . 



