62 MANGROVE SWAMPS 
tangal-lalaki (Mindoro); turgid (Jolo); tongog (Masbate); tagdsa (Ba- 
taan); pakat (Palawan); tonggui (Culion); tungog (Visayan); rongon 
(Zambales) ; ruingon (Pangasinan). 
The leaves of Ceriops tagal are from 5.5 to 7 centimeters in 
length and from 2 to 4.5 centimeters in breadth; the petioles, 
from 2 to 3 centimeters in length. The flowers are about 6 
millimeters long and are borne on short stalks. The calyx-lobes 
are oblong and somewhat blunt. The petals are oblong; the 
apex flat or notched and with three or more club-shaped append- 
ages. Stamens ten, nearly as long as the petals. 
Cériops candolleana H. & A. is a synonym of Ceriops tagal 
(Perr,) C. Bob: 
CERIOPS ROXBURGHIANA Arn. (Plates XXV, XXVI). TANGAL. 
Local names: Matangdl (Bataan); tangdl (Tayabas and Camarines) ; 
tungung (Surigao) ; bakduan (Bataan and Mindoro) ; bulubadidng (Panay) ; 
tungug (Negros). 
Ceriops roxburghiana has leaves up to 11 centimeters in length 
and 6 in breadth, petioles 1.5 to 3 centimeters in length. The 
flowers are about 5 millimeters long and about 5 millimeters 
broad and do not have individual stalks. The five or six calyx- 
lobes are short and somewhat pointed. The petals are oblong, 
white when young, turning to brown; the apex notched or 
slightly flattened and with a torn appearance. 
Genus RH!IZOPHORA 
Bakauan is the name given to the species of Rhizophora. 
These make up a very large part of the swamp and are often 
the most conspicuous constituent of it. 
These trees are distinguished from all others by their much- 
branched prop roots, which hold the trees up out of the water. 
This is perhaps the reason why the wood of these trees is usually 
sounder than that of others from the swamp. Besides the roots 
which come out from the base of the trunk, there are often large 
numbers of roots developed from the lower branches. The bark 
is very dark, almost black, coarsely ridged, and about 2 centi- 
meters thick. It contains a high percentage of tannin. 
The sapwood is yellow or whitish; the heartwood dark orange 
to reddish brown. The transition from sapwood to heartwood 
may be either gradual or abrupt. The wood is hard and heavy. 
The sapwood is 3 to 5 centimeters thick, and in old trees very 
sharply distinguished from the dark heartwood. The grain is 
straight and the texture fine and dense. It has a conspicuous 
