BY JOH> SHIRLEY. D.SC, AND C. A. LAMBERT. 4^ 



SPECIES OF Opuntia and Nopalea xaturalised ix 



QUEENSLAND. 



Species. I Habitat. 



Opuntia avrantiaca. Gill. . ,] Warwick, comniou about the l>anks of the 



Condamine. near the town. 

 „ Dilleiiii, Haw. . . Bii-sbane, (Tayndah, Rockhampton. 



ficus-indica, ^lill. Occasionally seen near deserted 3tation.s. 



etc., but usually reports of the preeence 

 of this pear prove to refer to 0. 

 tomentosa. 

 inermix, D.C. . . This is the pest jiear, said by Mr. Temple 



Clerk, in his booklet, " The Prickly 

 Pear Problem," to cover 30 million 

 acres in Queensland alone, and to be 

 spreading at the rate of one million 

 i acres a year. 



„ monacaniha. Haw. ; On both sides the Suttor River. 

 „ nigricans. Haw. . . | Yelarbon, S.W. Queensland. 

 „ tomentosa, Salm- j Dulacca, Gracemere. Helidon, Warra. etc. 

 Dyck 

 Nopalea coccineUifera, Mill. 

 „ dejecta, Salm-Dyck. 



Emerald. 

 Rockliami)ton district. 



4. — Histological Notes. 

 Besides specimens of Opuntia inermis. 0. aurantiaca^ 

 and O. monacantha, by the kindness of Mr. •!. F. Bailey,^ 

 Director, Botanic Gardens. Brisbane. v>e obtained 

 specimens of Cereus grandiflorus. Ha^.. Echinocactus 

 Eyresii, Luce., Peireskia aculeata, Mill., and Bhipsalis 

 salicornoides, D.C. These were all sectioned, and examined 

 under the microscope, the main study beinu centred on 

 the pest species. 



I. — Opuntia aurantiaca. Gillies. 



This species is so well armed with a close layer of sub- 

 cutaneous cells containing sphere-crystals of calcium 

 oxalate, as to be likely to defy all insect pests, and to 

 spread rapidly. It is provided with small, elongated- 

 ovate joints, and is easily recognisable by its reddish 

 epidermis, especially noticeable in yo\uig growth. 8ee 

 Plate III.. Fig. 1. The epidermal cells are from ^^ to J^ 

 mm. in length, by one-half those dimensions in breadth. 

 The outer wall is thickened with a deposit of cutiu until 

 it equals one-third the whole width of the cell, or ^\^ to 

 4^0 mm. 



The dermal layer is formed of five rows of cells, those 

 of the first layer lying immediately below the epidermis,. 



