718 PHARMACEUTICAL BOTANY 
EL’ATER.—An elastic, spiral filament attached to the spores of some Liverworts 
and Horsetails and aiding in their dispersal when mature. 
EMAR’GINATE.—Notched at the apex. 
Em’sryo.—A rudimentary plant found within the seed. 
Emsryo.’/ocy.—The study of the embryo and its development. 
Em’sryo-sAc.—A large cell within the nucellus of the ovule in which the embryo 
is formed after fertilization. 
En’pocArp.—The inner layer of the pericarp. The inner epidermis of the fruit 
wall. 
_ Enpo’permis.—A layer of cells forming the innermost boundary of the cortex and 
surrounding the central cylinder. Also applied to the bundle sheath surround- 
ing concentric bundles in the stems and leaves of pteridophytes and some 
monocotyledons. 
En’pocen.—A Monocotyledon. 
Enpoc’enous.—Applied to the axes of Monocotyl plants that do not increase 
materially in diameter. 
En’popuyTE.—A plant which grows within the tissues of another. 
En’pospeRM.—A storage tissue of the seed, consisting of the matured embryo sac 
around the embryo, and formed from the endosperm nucleus. 
En’posporE.—The inner wall of a spore. 
EnpoTHE’ciumM.—A zone of one or more layers within the exothecium of an 
anther. 
En’sIFORM.—Sword-shaped. 
EntTomMopH ILous.—Insect pollinated. 
ENn’TOPHYTE.—See Endophyte. 
En’zymes.—Nitrogenous, colloidal bodies closely related to the proteins and con- 
cerned with the chemical changes occurring in all living cells. 
EpHEM’ERAL.— Lasting for a brief period (a day or so). 
EpicA’Lyx.—A whorl of bracts resembling the calyx but below it. 
Epr’cArp.—The outer layer of the pericarp or the outer epidermis of fruits. 
Epicot’yL.—The portion of the embryo-axis above the cotyledon or cotyledons. 
Epwer’mis.—The primary outer covering layer of cells of plants, sometimes later 
replaced by cork. : 
Epic’ ynous.—Applied to floral leaves that appear to be inserted upon the ovary. 
EpipetT’ALous.— Upon the corolla. 
Ep’IpHyTe.—An air plant. A plant growing on another plant but not necessarily 
nourished by it. 
EpiruHe’L1um.—A delicate layer of cells lining an internal cavity. 
Eg’urraAnt.—Applied to leaves, as in Iris, when they all spring from a rhizome and 
are successively folded on each other toward their bases. 
EryTH’ROPHYLL.—The red coloring matter of leaves. 
EstivaA’t1ion (Aestivation).—The arrangements of the floral organs in the flower 
bud. 
Erz#’r10.—An aggregate fruit like the Raspberry or Blackberry, the product of a 
single flower, consisting of an aggregation of drupelets on a receptacle. 
E’r10LAT1IoN.—The bleaching of green parts of plants when kept in the dark for 
some time. 
Evorvu’tion.—The presumable theory that all forms of living things existing today 
have been derived from others previously existing, either by direct descent 
or by common ancestry. 
