166- SEDATIVE. 
SECURINEGA. See Oransits Myrrue. 
SEDATIVE. A medicine which diminishes 
irritability and represses spasmodic action. Nar- 
cotics are sedatives, but exert first a stimulating 
influence; and both these sedatives and others 
require to be used with caution, and are far too 
mighty agents to be handled by empirics and 
quacks. 
SEDGE. See Carex. 
SEDUM. A genus of ornamental plants, of 
the crassulaceous order. It has a very near rela- 
tionship to the houseleek genus. Fourteen spe- 
cies of it grow wild in Britain; 50 species or 
upwards have been introduced from other coun- 
tries ; and nearly 30 more are known. All the 
species in Britain, except two or three, are hardy ; 
and the great majority are perennial evergreen 
herbs. The leaves of almost all are alternate, 
fleshy, very succulent, and either flat, tumid, or 
cylindrical; and the flowers of most grow in 
cymes, and are either yellow, white, reddish, or 
purplish. Nearly all love a sandy loam; and all, 
except a few annuals and biennials, are propa- 
gated by division of the plant. 
digenous species are sometimes called house- 
leeks; but the greater number are more com- 
monly called stonecrops; and one of the best 
known is called Orpinn, and has been described 
by us under that name. All the indigenous spe- 
cles are perennials. 
The thick-leaved sedum, S. dasyphyllum, grows 
on old walls in England, and has a height of only 
2 or 3 inches, and carries white flowers in June 
and July.—The six-angled sedum, S. sevangulare, 
also grows on old walls in England, and has twice 
the height of the preceding, and carries yellow 
flowers in June and July.—The glaucous sedum, 
S. glaucum, grows on barren sands in some parts 
of England, and has a height of only 2 or 3 inch- 
es, and carries yellow flowers in July and August.— 
The whitish-leaved sedum, S. albescens, also grows 
on barren sands in England, but is more rare 
than the preceding, and has a height of 5 or 6 
inches, and carries yellow flowers in June and 
July.—The taper-leaved sedum, S. eretzfolvwm, is 
a rare indigen of some parts of Herefordshire, 
and has white flowers and a creeping habit.— 
The rock sedum, S. rupestre, inhabits the rocks of 
various parts of England, and has a height of 2 
or 3 inches, and carries yellow flowers in July 
and August.—The white sedum, S. album, also 
inhabits the rocks of England, and hasa similar 
height to the preceding, and carries white flow- 
ers in June and July. A small flowered variety 
of it, with a trailing habit, S. a. macranthum, 
occurs in Gloucestershire.—lorster’s sedum, 5S. 
Forsterianum, inhabits the rocks of some parts 
of Wales, and has a height of 2 or 3 inches, and 
carries yellow flowers in July and August.—The 
reflex-leaved sedum, S. reflecwm, inhabits old 
walls in England and Scotland, and has a height 
of about a foot, and carries yellow flowers in June 
and July.—The acrid sedum, S. acre, also inha- 
Some of the in-. 
SEED. 
bits the walls of Britain, but has a height of 
only 2 or 3 inches, and carries yellow flowers in 
June.—A dwarfish variety of it, S. a. diminutum, 
occurs on some of the heaths of England ; and a 
long-shooted variety, S. a. elongatum, is found in 
Suffolk.—The villous sedum, S. villosum, inhabits 
moist situations on the lofty mountains of Eng- 
land and Scotland, and has a height of 5 or 6 
inches, and carries pink flowers in June and 
July.—The oblong sedum, S. oblongum, inhabits 
the rocks of Britain, and is very dwarfish or only 
an inch or two high, and carries white flowers in 
July and August.—The English sedum, S. anglz- 
cum, also inhabits the rvcks of Britain, and is 
similar in height and bloom to the preceding ; 
and a distinct variety of it called the Irish, S. a. 
hibernicum, occurs in Ireland, and comes inte 
flower so early as June, and continues in bloom 
till August. A small-leaved and early blooming 
variety, S. a. microphyllum, occurs also in Britain. 
SEED. The repreductive epitome of a pheno- 
gamous plant. It is the grand provision for 
continuing and multiplying vegetable species ; | | 
and presents a considerable analogy in the vas- 
cular classes of the vegetable kingdom to an egg 
in the oviparous classes of the animal kingdom. 
Some chief things respecting the constitution of 
a seed have been stated in the articles Ovuz, 
Coryitepon, and ALBUMEN ; respecting the uses 
of many seeds for food and for economical pur- 
poses, in the articles AnimMenTARY PRINCIPLES, 
Foop or Animas, Orn, Ort-Caxe, Linsnep, Or- 
GANIC CHEMISTRY, and some others; respecting 
defects and losses of artificially sown seeds, the 
saving of corn-seeds, and the management of 
hybrid seeds, in the article AcGRicULTURAL 
SEEDS ; respecting the chemical changes which 
take place in the sprouting and growth of seeds, 
in the articles Gurmination and MALT; respect- 
ing the envelopes and the processes of ripening, 
in the articles Pericare and Fruit; respecting 
the proper artificial depositing of seeds for | 
growth, in the article Sowine ; and respecting 
the species, properties, uses, and treatment ofall 
the chief economical seeds, in the articles on the 
respective plants to which they belong, such as 
Wueat, Bartry, Oat, Pra, Bran, and multi- 
tudes of others. We shall, in the present article, 
therefore, do no more than make a few descrip- 
tive statements respecting seeds in general, and 
add some important practical remarks respect- 
ing the principal species of seeds employed in 
agriculture. 
Every seed, whether monocotyledonous, dico- 
tyledonous, or polycotyledonous, contains the 
embryo or rudiment of a future plant, and com- 
prises an ample and most beautiful provision for 
its protection during dormancy, and for arousing 
and feeding it at the time of germination. The 
foramen of the ovule or seed-vessel of the flower 
closes at the introduction of the pollen; the 
integument afterwards hardens; the juicy or 
pulpy contents increase and consolidate ; neur- — 
