374 GLOSSARY 
Lined. Rather lightly ridged or ribbed. 
Lobed. Divided rather deeply, as applied to leaves. 
Lucky-nuts or knots. A name sometimes given by children 
to woody structures imbedded in the bark of beech, olive, 
ete. They represent loosely attached rudimentary 
_ branches and are comparable with burls. 
Matted. Growing in very compact tufts, or so as to form a 
low close cover to the ground. 
Medullary rays. The plates radiating between pith and cor- 
tex in exogenous stems. Like pith, they serve for the 
storage of reserve food,—usually starch as may be demon- 
strated by a drop of iodine on the end of a twig cut in 
winter. 
Member. A morphological part of a plant: root, stem, leaf. 
Membranaceous. Thinner and less firm than coriaceous. 
Metamorphosis. Conversion of a member of the plant body 
into an organ differing in function from its usual form: 
tendril of grape (stem) or clematis (leaf) and aerial roots 
of poison ivy (root) as organs of climbing; spine of red- 
haw (stem) or barberry (leaf), or pea-tree (leaf rachis) 
as organs of protection; cladodia of butcher’s broom 
(stem), green roots of some conservatory orchids, etc., as 
foliage. 
Midrib. The strong main vein of a leaf. 
Milky. Colored, usually white, as applied to sap. 
Moniliform. Resembling a necklace of beads (sophora fruit). 
Monocotyledonous. Belonging to or characteristic of Monoco- 
tyledoneae, one of the two main groups of angiosperms. 
Morphology. The science of form in living things, classify- 
ing their parts as members from the view-point of origin 
and development. However they may differ in function, 
members that are morphologically of like origin are ho- — 
mologous one with another. 
Mucronate. With a short stiff abrupt point. 
Mucronulate. Minutely mucronate. 
