62 



out physiological experiments with many plants, 

 including the Cactaceis.* The surrounding 

 country with its rich cactus flora was examined. 

 In California the following localities were 

 visited:— Riverside (Botanic Gardens), Los 

 Angeles (East Lake Park), Palo Alto, San 

 Francisco, San Diego, Sacramento, Ohico, ana 



Santa Rosa. -o j. ir t 



At Palo Alto, a visit was paid to Prot. V ._ u. 

 Kellogg who had had some experience regarding 

 the destruction of prickly-pears by insect enemies. 

 At San Francisco, a number of porkers were con- 

 sulted in reference to our inquiry, amongst them 

 being Messrs. F. Maskew, chief deputy quaran- 

 tine officer, and G. Compere, chief inspector Cali- 

 fornia Horticultural Commission; Prot. C. M. 

 Woodworth and Dr. B. C. van Dyke, University 

 of California; F. E. Blaisdell, J. R. Slevm, and 

 Mr. Fuchs. Mr. Maskew and Mr. Compere kindly 

 offered to facilitate the transportation of any 

 cactus insects whose introduction into Australia 

 this Commission might think fit to recommend. 



San Diego was visited as a result of informa- 

 tion tendered by Dr. van Dyke and Mr. Blaisdell, 

 the local thickets of flat and cylindrical Opuntias 

 being carefully examined for the presence of cer- 

 tain injurious insects. Messrs. E. 0. Essig and 

 E. J. Vossler, of the California Horticultural 

 Commission, were interviewed at Saipramento, 

 but it was found that they had not given any 

 attention to the insect fauna of prickly-pears. 

 At Chico the Plant Introduction Garden belong- 

 ing to the Federal Department of Agriculture 

 was visited, and in company with Messrs. Beagles 

 and Krieger, Dr. GrifRth's large cactus planta- 

 tion was examined. Mr. Luther Burbank, the 

 well-known plant-breeder, was seen at his 

 nursery in Santa Rosa. 



The return journey to "Washington, D.C., 

 was made via Kansas, in the western portion of 

 which State field work was undertaken as a result 

 of information tendered by Mr. C. H. Popenoe, 

 of the Bureau of Entomology, during our stay 

 in Laredo, Texas. At "Washington further inter- 

 views were held with officers of the Bureaux of 

 Entomology, Plant Industry, and Biological 

 Survey, as well as with members of the staff of 

 the National Museum, in reference to prickly- 

 pear enemies. From "Washington the Com- 

 mission travelled southwards to Florida, where 

 one member carried out some investigations while 

 the other proceeded to the "West Indies to initiate 

 inquiry there. The following localities were 

 visited in that State :— Key West, Crescent City, 

 and Lake "Worth. 



Species of Prickly-pear Examined. — The 

 chief species which were examined by the Com- 

 mission in South-Eastern Texas were the 0. lind- 

 heimeri and 0. ferrugimspina, groups of species 

 (including 0. cacanapa, 0. texana, 0. leptocarpa, 

 and their allies), 0. leptocaulis, and certain low- 

 growing forms {EcMnocereus, spp.) known col- 

 lectively by Mexicans as pitalla. In the dry 

 regions occuring in Arizona and New Mexico, 

 attention was given mainly to the various species 

 of Cylindropuntia — the so-called tree cacti — such 

 as 0. fulgida, 0. arbuscula, 0. mammillata, 0. 

 versicolor, 0. spinosior, etc., -to the flat Opuntias, 

 0. engelmanni, 0. arizonica, and their allied 

 species, and to the giant cactus Carnegiea gigan- 

 tea. Others, such as 0- wootoni, 0. chhrotica, 



* Ann. Rep. Director of Botanical Besearch, Carnegie 

 Institution of Washington, Year-book No. 12, for 1913, 

 pp. 57-87. 



and 0. IcBvis were also examined. In Southern 

 California, the species of pnckly-pear (0. occi- 

 dentalis, E. and B. ; 0. prolifera, Eng.), occurring 

 commonly on uncultivated lands, were over- 

 looked, while in Kansas the low-growing 0. 

 missouriensis received most attention. 



At Key West, Florida, an Opuntia was 

 met with which differed from the typical 

 form of 0. dillenii* growing m the same 

 locality. It was a glossy green plant, whose 

 spines were rather longer, being commonly 

 4-5 to 5-5 cm. in length, rarely curved, more 

 gradually attenuated, and, when young, were 

 wholly reddish coloured, but became brown 

 with age The spines were less numerous, each 

 areole bearing from one to three, whereas m the 

 case of 0. dillenii, there may be as many as eight. 

 This Opuntia, which was not m flower or fruit 

 during the time of our visit, attained the stature 

 of dillenii when the soil was rich in lime, but 

 not otherwise. It was found to be less common 

 than the latter. At Lake Worth (Palm Beach) 

 both 0. dillenii and another prickly-pear were 

 seen, the latter resembling a stunted form of 

 the above-mentioned Opuntia met with at Key 

 West. A short visit to Crescent City failed 

 to reveal the presence of prickly-pear. It was m 

 'this locality that Opuntias were stated to have 

 been destroyed by a burrowing moth caterpillar, 

 Melitara prodenialis, Walker (Hubbard, 1895, 

 p. 129). The site of this former activity was 

 visited, but no cacti were seen there, though it 

 was afterwards ascertained that similar effects 

 were still being produced in a neighbouring 

 district. At Boat Key, which we did not have a,n 

 opportunity to visit, there occurs an Opuntia 

 which Dr. N. L. Britton has indentified as 

 0. inermis, and is quite distinct from any of the 

 prickly-pears seen by us in Florida. 



Localities in which prickly-pear was said to 

 be abundant, but which were not visited for want 

 of time, were the Indian River, near the sea, and 

 at Fort Pierce. Dr. Britton informed us that 

 a tuberous-rooted species, 0. austrina, grew 

 thickly in areas in Southern Florida. 



In addition to the various species mentioned 

 above, any others which came under notice were 

 also examined, among them being 0. bentonii, 

 Griffiths (1912 b, p. 26), an Opuntia from the 

 Southern States (Florida to Texas) very closely 

 resembling the Queensland 0. inermisA Various 

 species or varieties included under the name of 

 ' ' Mission Pear ' ' were met with along the south- 

 ern border of the United States, but always in 

 a state of cultivation or semi-cultivation. Atten- 

 tion was given to the collections of Cactaceae in 

 the botanic or other public gardens in New York, 

 Washington (D.C.), St. Louis, San Antonio 

 (Texas), Riverside (California), and Los Angeles 

 (Cal.), and in the plant introduction gardens at 

 Brownsville (Texas) and Chico (California). 



' A variety of 0. dillenii was met with in Florida, 

 with spines paler and somewhat more slender than those 

 occurring in the typical plant. It evidently approached 

 in character Opuntia tuna as interpreted by Britton. It 

 grew along with the typical form of O. dilUnii, 

 and was apparently indistinguishable from it except in 

 respect to the character mentioned. O. opuntia is more 

 commonly known under the name G. vulgaris, Mill. 

 Mr. BurkiU (1911, p. 287) refers to it as O. nana, Visiani, 



and mentions, apparently in error, that its home is Central 



America, instead of Eastern U.S.A. 



t 0. allairii, Griffiths (19096, pp. 83, 84), from 



Eastern Texas, also seems to be related to our Dulacoa 



pest pear. Specimens of O. bentonii were seen in the New 



York Botanical Gardeits, 



