84 proceedings of the academy of [1883. 



April 10. 

 Rev. H. C. McCooK, D. D., Vice-President, in the chair. 



— — , _ _ — , _. 



Thirty-two persons present. 



Notes on Echinocactua. — Mr. Thomas Meehan announced, at 

 tlie meeting of the Botanical Section, the discovery of sensitive 

 stamens in Echinocactus Whipplei. This peculiarity had been 

 long known in Opuntia Rafinesqui and allied species, as well as in 

 Fortulaca., which, though its natural order was regarded as very 

 distinct in systems of classification, had much in common with 

 Cactaceae. The motion of the stamens when touched in this 

 species of Echinocactus was not instantaneous, several seconds 

 sometimes elapsing before the motion responded to the touch. 

 The flowers of this species are unable to expand to any great 

 extent, on account of their short tube, surrounded by long and 

 stiff spines. If the flowers could expand as in Opuntia^ and the 

 stamens lie flat, as in that genus, Mr. Meehan suggested that the 

 motion might be equal to that observed in Opuntia. The motion 

 in Opuntia was not always up towards the pistil, but might be 

 horizontal, to the rigiit or to the left — there seemed to be no rule. 

 That seemed to be the case also in the Echinocactus. The bending 

 was from the base, as the filament retained a perfectly straight 

 line during the movement. 



Mr. Meehan further remarked that in descriptions of cactaceous 

 plants, the relative length of the pistil to petals or stamens was 

 often given. He had observed that in many species, about the 

 period of the ejection of the pollen from the anther-cells, the 

 stamens and style were of about equal length, the stellate stigma 

 being just above the mass of anthers ; but the style continued to 

 grow after the maturity of the anthers, and, in Echinocactus 

 Whipplei^ would finally reach to near half an inch above. He 

 had not been able to get any genera of Cactaceae to fruit under 

 culture except Opuntia,.^ unless they were artificially pollinized. 

 By the application of the flower's own pollen to the stigma, they 

 sometimes i)erfected fruit. 



Mr. Meehan also remarked that in botanical descriptions, 

 Echinocactus Whipplei and Echinocactus polyancislrus were 

 described as having greenish or yellow flowers. His plants had 

 bright purple flowers, and he had no doubt wei'e correc ly referred 

 to the species named. They were from southern Utah. 



Referring to Echinocactus uncinatus., he remai'ked that speci- 

 mens collected in New Mexico by George Vasey, and blooming 

 under culture, had the central spine double the length of the 

 others, whereas in the figure in Pfeiffer they are all represented 

 as uniform, and there were no green-edged sepals or bracts at the 



