496 XXV. HAMAMELIDACEAE 



2. PARROTIA, C. A. Meyer. 



Parrotia Jacquemontiana, Dene. Himalayan witch-hazel. Vern. Pdser, 

 kildr, shtar, Punjab. 



A large gregarious deciduous shrub or small tree, strongty resembling 

 a hazel, occurring between 3,000 and 8,500 ft. in the Himalaya from the 

 Jumna westward. It is used chiefly for wicker-work for the walls of houses 

 and for rope-bridges, the twigs being flexible and very tough : it is also used 

 for walking-sticks and other purposes. Silviculturally it is of importance 

 owing to the abundance with which it springs up as an underwood in certain 

 localities. It coppices very vigorously, stands a certain amoujit of shade, and 

 forms dense masses which impede the reproduction of deodar, blue pine, 

 and other trees. It is a good soil-improver, and if it can be kept down 

 sufficiently to allow young deodar and pine to penetrate its cover they grow 

 well : the only means of ensm-ing this seems to be to cut back the Parrotia 

 repeatedly, a costly operation owing to its vigorous power of coppicing. 



ORDER XXVI. RHIZOPHORACEAE 



This order comprises for the most part a number of littoral species collec- 

 tively known as mangroves, which, together with certain species belonging to 

 other natural orders, make up the curious littoral forest formation known as 

 mangrove swamp. Of non-littoral species the most important is CaraUia 

 lucida, Roxb. 



Mangrove swamp. Mangrove forest is found in littoral regions through- 

 out the tropics, not along sandy beaches or rocky shores which are exposed to 

 the full force of the wind and the waves, but in the estuaries of rivers, in creeks 

 and lagoons, and on low islands where the force of these agencies is not so 

 strong. In such places the mangrove belt occupies a strip of low-lying muddy 

 ground, subject to inundation by ordinary tides, the strip varjdng in width 

 from less than a hundred yards to several miles. 



Distribution and species. In a classification of the mangrove forma- 

 tions of the world two broad but well-defined areas are distinguishable an 

 eastern area embracing East Africa, Asia, and the Polynesian Islands do\\ai 

 to Australia, and a western area comprising the coasts of America and West 

 Africa. The species in the respective areas are distinct, but the eastern area 

 is far richer in species than the western. The most extensive and highly 

 developed mangrove forests are found in the Malayan region, and particularly 

 in the island of Borneo, where the configuration of the country favours the 

 formation of mangrove swamps over large areas in the coastal regions.^ 



In the Indo-Burman region the mangrove forests are distributed to 

 a greater or less extent in suitable localities throughout the coastal regions, 

 from the delta of the Indus in Sind southwards along the west coast of the 

 Peninsula down to Travancore, from the Sundarbans southwards along the 

 east coast of the Peninsula and down the coast of Chittagong, Arakan, and 

 Burma ; also along the coast of the Andamans and adjacent islands. The 

 mangrove forests of Arakan are estimated to cover 948 square miles, while 

 1 Distribution and Utilization of the Mangrove Swamps of Malaya, F. W. Foxworthy, 1909 

 (Ann. Jarcl. Bot. Buitenzorg, 2" s6r., Suppl. HE). 



