282 
AMENTACEJE. 
— A large tree without suckers. L. remarkably triangular. Young 
shoots glabrous. Scales of the catkins palmately cut smooth. — 
Damp places, river-banks. T. III. Black Poplar. 
Tribe II. Myricece. 
3. Myrica Linn. 
1. M. Gale (L.) ; L lanceolate broader upwards serrate, st. 
shrubby.— E. B. 562.— Height 3—4 feet. Bushy. Catkins 
sessile, erect. Fr. with resinous glands. L. fragrant \vl7en bruised. 
— Bogs. Sh. V. Sweet Gale. Bog Myrtle. 
Tribe III. Betulinece. 
4. Betula Linn. 
1. B. alba (L.) ; I. rhomboid-triangular doubly serrate acumi- 
nate, scales of the fem. catkins 3-lobed, lateral lobes deflexed, 
middle lobe ascending, fr. obovate-elliptical shorter than the 
rounded membranous margin. — E. B. 2198 (upper fig.). B. alba 
Fries ! — L. usually glabrous, often covered with resinous spots 
above, always having a manifest tendency to a rhomboidal form. 
Young shoots mostly with resinous tubercles. Readily distin- 
guished from the following by its leaves but more certainly by 
the fruit. Young twigs often very long and pendulous. — Rather 
common. T. IV. V. White Birch. 
2. B. glutinosa (Fries !) ; I. cordate-ovate unequally serrate 
acute, scales of the fem. catkins 3-lobed, lateral lobes ascending, 
middle lobe patent or reflexed, fr. broadly obovate as long as the 
rounded membranous margin. — E.B. 2198 (lowerfig.). B.pubescens 
Koch. — L. usually glabrous always more or less ovate. Not so 
elegant a tree as the preceding and often little more than a bush. 
Twigs sometimes pendulous. — /3. pubescens (Fr.) ; 1. peduncles 
and young twigs downy. B. pubescens Ehrh. — Common. T. IV. V. 
Common Birch. 
3. B. nana (L.) ; I. orbicular crenate glabrous : crenations ob- 
tuse, scales of the fem. catkin digitate-trifid divided almost to 
their base : lobes equal, fr. orbicular with a very narrow mem- 
branous margin. — E. B. 2326. ? — A small procumbent shrub 
with minute leaves and little catkins. B. nana Fries !, Reich. !, 
Tausch ! — /3. Linneei ; scales of the fem. catkins 3-lobed divided 
through only half their length, fr. elliptical with a narrow mem- 
branous margin. B. nana Linn. .' Herb. Exactly resembling 
var. x. except in the structure of the fructification. Probably a 
distinct species. — Turfy places in the highlands. Of ce. the only 
specimens that I have seen are from Ben Lawers. /3. is com- 
mon. Sh. V. Dwarf Birch. S. 
