* 
162 
THE DICTIONARY OF GARDENING, 
Hydnum—continued. 
sliced into hot water, and gently pressed, should be care- 
fully stewed, or rubbed down into a purée. 
NAV 
Fig, 251. HYDNUM REPANDUM. 
HYDRANGEA (from hydor, water, and aggeion, a 
vessel; in allusion to the cup-shaped fruit). Syn. 
Hortensia. ORD. Savifragew. A genus consisting of 
thirty-three species of greenhouse or hardy, deciduous or 
evergreen, showy .shrubs or trees, natives of Eastern 
Asia, Java, the Himalayan Mountains, North-west and 
South-east America. Petals four or five; calyx superior, 
five-toothed; stamens eight to ten; capsule membran- 
aceous. Leaves opposite, petiolate, persistent or deciduous, 
entire, serrate, or lobed. Hydrangeas are of easy cul- 
ture, and are exceedingly ornamental for conservatory, 
room, or window decoration. They are also well adapted 
for growing in the open ground, in all the warmer parts 
of the country. The sorts having abortive or sterile 
flowers, with an enlarged calyx, are the most orna- 
mental, and are extensively grown. H. hortensis, and 
some of its varieties, have nearly all sterile flowers, 
and are, consequently, most popular. H. paniculata 
grandiflora is very handsome, and amongst the best, 
either for pot culture or for outside treatment. The 
American species are hardier, but not so ornamental, 
as those from China and Japan. Propagation is readily 
effected from cuttings of young or partially -ripened 
shoots, which may be inserted at almost any time when 
they are procurable. Old plants may also be divided for 
propagation. For culture outside, a somewhat sheltered 
position should be selected, except in favourable localities. 
Cultivation in Pots. Hydrangeas may be propagated 
annually to produce one head of flowers each—a method 
largely practised—or they may be grown as shrubby 
plants several years in succession.’ Cuttings should be 
inserted in small single pots, and plunged in a close, 
warm frame. They may be taken in spring, from young 
growths that are not bearing flowers, and be grown on 
throughout the summer, and well ripened in autumn by 
exposure outside. Another plan is to Jet the old plants 
grow all the season, and put in strong points as cuttings_ 
when partially ripened. In this case, the formation of 
roots only should be encouraged, by plunging in a little 
bottom heat, but not in an inclosed frame. Select the 
tops of the strongest and most prominent shoots for 
‘cuttings, and insert them in August. When they are 
rooted, gradually harden off, and expose them to full 
sunshine and plenty of air in autumn, to insure thorough 
ripening. When the leaves fade, water should be with- 
held, and the plants kept dry, in a cool greenhouse, all 
the winter. In February, or earlier if desired, they 
may be potted into 5in. or 6in. pots, and started by 
acing in a higher temperature, and applying more 
water. The embryo buds, formed the previous autumn, 
will soon begin to expand; but it is not usual for all 
Hydrangea—continued. 
to flower, as they may not have been sufficiently strong. 
As a rule, the corymb of flowers appears after the 
fourth pair of leaves; and should the plant develop so 
far without the embryo being seen, it may be thrown 
away, unless required for another year. Late autumn- 
struck cuttings produce useful dwarf-flowering plants 
in spring, not exceeding lft. in height. Those propa- 
gated in spring, and grown on in pots for the next 
year, are much stronger and taller in proportion. A 
new stock should be propagated annually, and the old 
ones thrown away, unless required for bush specimens 
or for supplying cuttings, when they may be cut down, 
repotted, and grown on in pots, or be planted out in 
the open air. Hydrangeas like a rich soil, such as loam 
and decayed cow or other manure in equal parts. Any 
quantity of water may be applied in the growing 
season; and artificial manure, given just as the flowers 
are developing, invariably proves beneficial. The flowers 
sometimes turn blue, certain soils having the property 
of changing the normal colour, in consequence of the 
presence of some chemical constituent. Water,.in which 
alum has been dissolved, is used artificially to cause the 
same change in colour. Iron in small quantity, as well 
as some other substances, mixed with the soil, are said 
to produce the same effect. In some gardens, plants 
that produce red flowers one year may develop blue 
ones the next, and this without any influence or skill 
on the part of the cultivator. 
H. ar iS (tree-like), fl. white, small, having an agreeable 
odour, nearly all fertile; corymbs flattish. Summer. l. ovate, 
rather cordate ; upper ones lanceolate, coarsely toothed, pale and 
puberulous beneath. A. 4ft. to 6ft. North America, 1736. 
Hardy. (B. M. 437.) 
Fic. 252. HYDRANGEA HORTENSIS. 
H. hortensis (garden).* Common Hydrangea. fl. varying much 
in colour (according to the soil in which the plant is grown), dis- 
posed in ample corymbs or cymes, all difformed ; fertile flowers 
few. April to September. /. broadly-ovate, serrated, acuminated. 
t. to 3ft. China, 1790. SyN. Hortensia opuloides. See 
. The varieties of this species are numerous; one of 
the most noteworthy being “Thomas Hogg,” a form with pure 
white flowers. : 
H. h, japonica (Japanese). fl. blue, white, difformed; cymes 
crowded. l: ovate-oblong, acuminated, finely and glandularly 
serrated, glabrous. h. Japan, 1843. The varicty roseo 
has the outer flowers only radiate, and either white or rosy 
toothed ; and ewrulescens has bright blue ray-flowers. 
— are also forms having leaves with gold and silver varie- 
on. 
