CACTUS FAMILY (CACTACEAE) 



176. Tuna de petate, pricklypear 



Distinguishing characters of this large treelike 

 cactus ai^e: (1) numerous spines, 1-6 together 

 spreading in a cluster with a tuft of needlelike 

 hairs at base, or spines sometimes absent; (i3) 

 erect rounded fleshy spiny tiimk with bark pa- 

 peiy or scaly, bearing as branches flat, oblong 

 to obovate, dull gray-gi-een to dark green or red- 

 dish-green joints or pads, 6-16 inches long, spiny 

 and fleshy; (3) essentially leafless, the leaves be- 

 ing minute gi'een fleshy scales located singly at 

 base of clusters of spines; (4) orange, red, or 

 yellow flowers •% indi across the many petals, 

 borne on an oblong tubercled spiny green ovary 

 11/^-2 inches long; and (5) red fleshy fruit a pear- 

 shaped or rounded berry 2-3 inches long, spiny 

 or spineless. A spineless form of this species oc- 

 curs in Puerto Rico. 



A cactus 10-15 feet tall, with trunk ^6 inches 

 in diameter, not jointed, erect and unbranched 

 for a few feet. The reddish-brown trunk be- 

 comes furrowed and flaky, retaining many gray 

 spines 1-2 inches long in radiating clustere. 

 There are several stout spiny branches ascending 

 and ending in several spreading to horizontal 

 flat si^iny joints. They continue or branch. 1-3 

 at the end of an older joint. A definite crown 

 of foliage is not present. 



The leaves are borne at a cushion (areole) of 

 many small, needlelike, fine, stifi', brown hairs and 

 cluster of spines which corresponds to a node. 

 Though the leaves fall, the flashy joints are ever- 

 green and function yearlong like leaves in food 

 manufacture. There are 1-6 needlelike whitish 

 spines 14-2 inches long, spreading from a center. 



Flowers are borne singly and stalkless on the 

 terminal joints, 1-3 on the edges of a joint, located 

 at the cushions of needle hairs. The largest part 

 of the flower is the inferior tubercled and usually 

 spiny gi-een ovary 11/2-2 inches long and 1% 

 inches in diameter. The calyx is composed of 

 many fleshy sepals. The petals are obovate, mi- 

 nutely pointed, and spreading. There are very 

 many stamens about half as long as the petals and 

 a central style bearing the stigma with several 

 rays. 



Opuntia rubescens Salm-Dyck 



The fruit is the enlarged ovary, usually spiny. 

 There are many seeds less than 14 inch in diam- 

 eter. Flowering and fruiting nearly through the 

 year. 



Beneath the bark is liglit yellow, soft watery 

 tissue, almost tasteless, and inside is the light yel- 

 low, fibrous wood. 



As in certain other species of cacti, some fruits 

 proliferate, that is, grow to form new flowers at 

 the ends. Upon falling to the ground, these easily 

 detached ovaries develop roots and grow into 

 new plants around the parent, directly and veg- 

 etative ly, rather than through seeds. Likewise, a 

 joint on the soil can begin a new plant. Vegeta- 

 tive propagation in this manner is more direct and 

 more certain in dry areas than seed germination 

 and establishment of small seedlings. 



Like the columnar tree cactus, tuna de petate or 

 pricklypear is adapted to a hot and very dry cli- 

 mate. It has a shallow root system, water storage 

 tissue in the fleshy joints, reduced surface area, 

 and reduced water loss (transpiration) . 



This species is often an undesirable plant where 

 common. The spineless form has been introduced 

 into cultivation in gardens in Puerto Rico. 



Scattered in dry forest on plains and hills at low 

 elevation in southern and southwestern Puerto 

 Rico and rare at Cape San Juan in the extreme 

 northeastern corner. Also on Mona ( ? ) , Icacos, 

 Culebra, and Vieques. Through Virgin Islands on 

 St. Croix, St. Thomas, St. John, Tortola, and 

 probably smaller islands. 



Public forest. — Guanica. 



Range. — Mona ( ? ) , Puerto Rico and smaller ad- 

 jacent islands, through Virgin Islands, and St. 

 Martin to Guadeloupe in Lesser Antilles. 



Other common names. — tuna de yagua, tuna 

 (Puerto Rico) ; tree cactus (Virgin Islands) ; 

 petites raquettes (Guadeloupe). 



Botanical s t n o n t m. — Consolea rubescens 

 (Salm-Dyck) Lemaire. 



This genus of pricklypears is represented by 6 

 other native species not reaching tree size and by 

 a few others introduced for ornament. 



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