NO. 9 NEOABBOTTIA, A NEW CACTUS GENUS BRITTON AND ROSE 5 



elk. This arrangement is shown in the mature tree, although the 

 intermingling of the several branches gives the general effect of an 

 ordinary tree-top. 



" The natural pruning of the tree comes about through the death 

 of branches caused by epiphytic plants, the breaking off of branches 

 by the weight of a clambering cactus, and the attack of insects which 

 live in the fleshy joints. These insects are much sought after by a 

 red-headed woodpecker. 



''' Flowers are borne at the extreme tip of the terminal joints and 

 never from the sides, the fruit appearing therefore always at the 

 tips. A single fruit always grows directly in line with a rib, but when 

 several fruits grow from the same terminal bud they are compelled 

 to radiate at right angles to the axis of the joint. Four fruits from 

 one joint is the highest number observed, two only usually appearing 

 to be normal. As the ovary develops the flower shrinks, dries, and 

 appears finally as a brown protuberance attached to the apex of the 

 mature fruit. The old flowers at length fall off the mature fruit, 

 leaving a well-defined umbilicus. The fruit measures 6f to 7 inches 

 in circumference. When ripe it is waxy, smooth, yellow with faint 

 streaks of pink radiating from the base ; flesh same color as rind, 

 glutinous, firm, slightly acid to taste, hardly edible. 



' Seeds are embedded in a secretion which in water produces a 

 remarkable bulk of mucilaginous jelly, which is mildly acid and not 

 unpleasant to taste. Fruit does not seem to be attacked by birds and 

 is never eaten by natives. Successive crops of fruit appear from 

 this same bud cluster at the top of the terminal joint, each crop absorb- 

 ing some of the substance of the joint ; the joint shrinks and solidifies, 

 the ribs become furrows, the center enlarges, and finally all becomes 

 a woody mass of varying dimensions, as long as 3 inches, thus 

 forming what you have called a ' cushion,' but which is reallv an 

 atrophied joint after several years of fruit-bearing." 



The nature of the cephalium is not well understood, but it seems 

 to be an abortive joint. It first appears like a large felted areole 

 from which several flowers are produced; it slowly elongates and 

 finally becomes 7 cm. long or more, still producing the flowers at the 

 tip. When very old most of the felt wears off, leaving a stubby 4 

 or 5-angled joint ; the areoles, however, are not borne on the angles 

 as in normal branches, but in the depressions or furrows between the 

 ridges. In these furrows the areoles form a continuous band of felt 

 from the base to the top of the joint. One of these flower-bearing 

 joints which Mr. Pilkington has sent is 5 cm. long and we have esti- 



