104 



9. Chiqueciiique de Cabeca Branca; 

 Cabeca Branca (The White-headed Chique- 

 chique). — This species of Cephalocereus is 

 extremely common between Bomfin and Angico 

 and at the latter place, though it does not seem 

 to occur at Bomfin. It branches at the ground to 

 form numerous tall, simple round stems from 6 

 to 10 or more feet in height, each stem bearing 

 abundant small ridges with very numerous thin 

 yellowish spines an inch long, as well as a great 

 quantity of "wool," especially on the distal 

 portion. 



10. Between Jaguarary and Bomfin in the 

 schist country, one may see from the train a very 

 tall, thin, straight Cereus with a rounded stem. 

 With the exception of an occasional tree-cereus 

 (Mandagaru de boi), cacti were not evident in 

 that type of country. 



11. Palmadoba (The Spiny Palmadoba). — 

 The name palmadora is often applied to any 

 Opuntia, but in the districts visited, it is generally 

 used to designate a species with rather small, 

 thin joints armed with abundant brittle, white or 

 pale yellowish spines (darkening with age) four 

 to six on each areole, the longest being about an 

 inch in length. It is an erect plant and seems to 

 prefer shade conditions, where it may reach a 

 height of 8 feet, its usual height being about 5 

 feet. The green fruit on reaching the ground 

 readily grow. This Prickly-pear is very common 

 and is far less restricted in range than the next 

 species to be mentioned. 



12. CuiPA (the Palmadora without evident 

 spines). — This very low-growing plant, 0. cuipa 

 Web. Syn. 0. inamasna, Sch. (1899, p. 742; 1890, 

 p. 306) is common near Angico, though it is also 

 to be met with occasionally near Bomfin in drier 

 situations. In the former locality it is known as 

 Cuipa, whereas in the latter it does not seem to 

 have received a special name. Weber has attached 

 the name to a plant of quite similar habit, but 

 armed with two or three weak spines in each 

 areole (Schumann, 1903, p. 162). The edible 

 fruits are orange or yellowish in each case. Its 

 locality is stated to be Pernambuco. In 0. ina- 

 rncena one may find one or two very small spines 

 on each areole as described for 0. cuipa, but they 

 readily fall off. This explains Schumann's 

 description of the species as unarmed. The two 

 names are synonymous, 0. cuipa possessing 

 priority. 



13. Palmadoba Grande. — This plant, which 

 is not indigenous, resembles the Mission Pear (0. 

 castillce, Griffiths) of South-Western United 

 States of America, and probably belongs to that 

 species or to 0. ficus-indica. The young plants 

 have abundant white spines and resemble 0. 

 amyclea in appearance, but the spines generally 

 drop off later. It is more or less cultivated for 

 the sake of its joints, which are fed to stock. 



Schumann (1899, p. 718) in his account of 

 Pilocereus exerens, Sch., mentions 'that it occurs 

 in the States of Bahia and Pernambuco and that 

 it is called " Fascheiro" by the natives. As 

 detailed descriptions of the various species met 

 with were not taken, the identification of this 

 Pilocereus with any of the above is not attempted. 

 The same author refers to a few other cacti from 

 Bahia, e.g., 0. monacantha, Rhipsalis, &c., but 

 they probably belong to tlie moister and more 

 wooded areas of that large State. 



DESTRUCTION BY DISEASE. 



No fungoid or bacterial disease of any value 

 in controlling the spread of Prickly Pear was 

 seen during the investigations in South America. 



Shot Hole Disease. — The Shot Hole Fungus 

 (probably Oloeosporium lufiatum) was encoun- 

 tered in widely separated localities. The injuries 

 produced by it have already been referred to in 

 the section dealing with our work in the United 

 States of America. The black rot which it causes 

 under damp weather conditions in Southern 

 Texas, does not seem to occur under the more arid 

 climate of Western Argentina and Bahia. It was 

 found on the Uruguayan species 0. arechavaletce, 

 Speg. (allied to 0. monacantha) and on 0. 

 chakensis, Speg., at La Plata; on 0. ficus-indica 

 in Buenos Aires ; at Bomfin and Angico on both 

 0. cuipa and the spiny Palmadora. Occasionally 

 gumming was associated with the injury. 



Wolf (1912, p. 112) refers to the presence of 

 a Gloeosporium, G. opuntice, Ell. and Ever., on 

 0. brasiliensis, which is a South American species. 



White Rot; Sclcrotium Disease. — What is re- 

 garded as a much more serious fungoid disease 

 is that caused in Argentina by Sclerotium opun- 

 iiarum, Speg. (1898, p. 354), whose perfect stage 

 is Sclerotinia opuntiarum, Speg. (1899, p. 18). 

 In his description of the latter stage of this fungus 

 Dr. Spegazzini states (p. 19) that the parasite is 

 a formidable enemy of all Cactacese, especially 

 during winter. A white cotton-like mass of 

 mycelium becomes developed below the epidermis 

 in the parenchyma, which becomes destroyed and 

 putrefies. Sclerotia are produced and then 

 liberated, and from them develops the asco- 

 pore stage in the following autumn. A search 

 in company with Dr. Spegazzini failed to reveal 

 its presence at La Plata (Jan., 1914). This 

 botanist in 1910 recorded the occurrence of the 

 Sclerotinia stage, S. opuntiarum, in rotten trunks 

 of Pilocereus formosissimus. Lab. (= Cereus 

 posacana, Weber, in Schumann, 1899) near 

 Mendoza. 



The same malady is referred to under the 

 name of gangrena blanca, i.e., the white rot, by 

 an anonymous writer in the Chronica Agricola 

 (Buenos Aires), 1908, pp. 147-8, who calls the 

 fungus Sclerotinia cactorum. In order to decrease 

 the ravages, he suggests the frequent inspection 

 of plants and the destruction of those found to 

 be infected. 



The introduction of this Sclerotinia into 

 Queensland is not at present recommended. 



In 1898 Dr. Spegazzini (1898, p. 353) gave 

 an account of another Sclerotium, S. cactorum, 

 but has not included it as such in his later work 

 on the Argentine fungi. Perhaps it is synony- 

 mous with his S. opuntiarum. 



Other fungi have been described as occurring 

 parasitically or saprophytically on South Ameri- 

 can Cactacese by Spegazzini, but they are of little 

 or no economic importance. 



Amongst these are Perisporium men- 

 dozanum, Speg., 1899, p. 227, found on P. 

 aoracantha near INIendoza ; JEcidivm opun- 

 tim, Magn., found by Magnus (1898, p. 

 151) on a Bolivian Opuntia and by 

 Spegazzini on 0. digitalis in Argentina 

 (Speg., 1909, p. 321) ; Trulla nigerrima on 



