THE RHUBARB. 
563 
covered with lichen, a sure sign that it will 
not increase further in bulk. It should then, 
of course, be cut down. On lands which are 
not much exposed, and where the subsoil is 
free, the Scotch pine will attain maturity in 
about fifty years ; and on its proper habitation, 
the hills, it will continue increasing till about 
seventy or eighty years of age. It is impos- 
sible, however, to fix a scale applicable to all 
the situations and soils which it may happen 
to affect, and the planter must himself exercise 
his judgment both as to the state of the tree, 
as well as to the purposes for which the timber 
may be required. For flooring, and house- 
carpentry in general, mature trees are to be 
preferred ; for scaffolding, trees of forty years 
of age, grown on " middling good soil," are 
better than any others. The best season of 
the year for felling is from October till March, 
whea the juices are at rest. 
THE RHUBARB. 
Under the common designation of Rhubarb, 
several distinct species have got into cultiva- 
tion, and at the present day no doubt they 
are variously mixed together in the varieties 
which are every year raised from seed, such 
being the common and natural method pursued 
by the great growers of this vegetable for the 
London markets. The enormous quantities of 
this one article alone frequently exhibited in 
Covent Garden on one morning, independent 
of the other markets, would, of itself, give a 
stranger a good idea of the enormous popula- 
tion it has to be distributed amongst, and 
which have to be daily supplied, not alone with 
( j comparative luxury brought to market in 
j umbers of vans drawn by four and six horses 
, ach, but also with the commonest necessaries 
f life. 
i The number of species of rhubarb known 
s upwards of twenty, and at least sixteen are 
introduced to this country. The head quarters 
of the genus seems to be on the table lands of 
the central parts of Asia, where they appear 
to affect the rocky declivities of the hills, 
growing on the borders of woods and in bushy 
places. One species, Rheum a it stria cum, pene- 
trates into eastern Europe, whilst jR. undula- 
tum is found in China, they thus appearing to 
follow the ranges of mountains which occupy 
b ie higher parts of that enormous conti- 
ent. 
u It- nas long been a contested point as to the 
"pecies which produced the medicinal root, 
r nd although it was long settled that the 
Turkey and the Chinese must be the produce 
'•f different plants, it was not so easy to decide 
Much were the plants. But there can be 
little doubt that the collectors of the roots are 
'more liable to take every good root they see, 
than to stop to look as to the peculiar sort 
it might be ; for it can hardly be expected 
that any one of the species grows so exclusively 
alone as to be always selected for medical 
purposes. This will apply whether the collec- 
tors are Turks, Bucharians, or Mongols. 
Rheum Rhaponticum appears to be a 
native of western Asia, and to have been 
known in this country since 1573. It has 
large cordate, pointed leaves, much waved 
on the edges, the expansion of the leaves 
being elevated between the ribs and veins. 
Leaf-stalks, with a broad but shallow furrow, 
rounded on the edges, on the upper side, and 
of a bright red colour. The flavour of the 
leaf-stalk is sharp, acid, and pleasant, with less 
of the medicinal flavour than almost any of the 
others. This is supposed to be one of the 
sorts collected for the Turkey market ; and is 
also very extensively cultivated in England. 
Rheum hybridum is also a native of Asia, 
and was introduced in 1573. Leaves large, 
cordate, blunt or rounded at the end, in a 
young state wrinkled between the ribs. Leaf- 
stalks with a broad shallow furrow above, and 
of a dark red colour. The flavour is more 
medicinal, and not so pleasantly acid as the 
above. This appears to be the sort the giant 
varieties are raised from ; and it is esteemed 
more succulent than the first by some. 
Rheum palmatum is a native of Bucharia, 
introduced in 1763, and is by many considered 
as furnishing the Russian rhubarb of com- 
merce. It is easily distinguished from all the 
others by its palmate leaves, acutely toothed 
or jagged, and by its round leaf-stalks, of a 
greenish colour, thickly spotted with small red 
spots. It has a very slightly acid, rather me- 
dicinal flavour, but appears to be more destitute 
of flavour in a young state than any of the 
others. 
Rheum undidatum is a native of China, 
and was introduced in 1734. It has cordate 
leaves, lengthened into a point, and much 
waved at the edges. The leaf-stalk has a very 
slight furrow above, and is of a red colour 
about half way up. It is not so high flavoured 
as the first sort, and has a slightly medici- 
nal taste. It appears to be decidedly the 
earliest species, and on that account worthy 
of attention. 
Rheum caapiciim is a native of the Russian 
provinces near the Caspian sea, and was 
introduced in 1817. The leaves are cordate, 
wrinkled, and undulated at the edges, and it 
approaches the last in appearance. Leaf-stalks 
broadly furrowed above, of a dull red colour, 
and very coarse in the flesh, which possesses 
little acidity, and has a strong medicinal 
flavour. 
Rheum comparlum is a native of Tartarv, 
and was introduced in 1758. Leaves cordate, 
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