GLOSSARY OF BOTANICAL TERMS. 17 



Interpetiolar, stipules placed between the petioles of opposite leaves. 

 Interrupted, having bare spaces between the parts. 



Involucel, (1) the involucre of a partial umbel; (2) the outer calyx in Dipsaceae. 

 Involucre, a number of bracts surrounding the base of a flowerhead or of an 



umbel. 

 Involute (inrolled), with the edges rolled inward, as in the leaves of many grasses. 



Irregular. — This term is used in its strictest sense to describe those rare 

 asymmetric flowers which cannot be divided into two equal halves through 

 any vertical plane (such as the V a'erianaceae) . It is here applied in a 

 more general sense to a flower in which the parts of either the calyx or corolla 

 are dissimilar in size or shape. It therefore includes flowers which are 

 altogether asymmetric and those which are zygomorphic, or bilaterally 

 symmetrical, i.e., which can be cut through only one vertical plane into two 

 equal and similar halves (Peaflowers, Pelargonium, Violet, &c). 



Joint, see article. 



Keel, (1) a projecting ridge along the middle of a flat or convex surface; (2) 

 the two partially united lowest petals of pea-shaped flowers. 



Kernel, see drupe. 



Labellum, (1) the lowest petal of orchids, usually different in form from the two 

 lateral ones; (2) the lowest petal of Stylidiaceae. 



Labiate, lipped; where the limb of a corolla is divided into two parts, called an 

 upper and lower lip. 



Lacerate, jagged. 



Lamina, the blade of a leaf, or the expanded upper part of a petal, sepal, or 

 bract. 



Lanceolate, shaped like the head of a lance, tapering at both ends. 



Leaflet , each division of a compound leaf. 



Ligulate, having the limb of the corolla strap-shaped, as in many Compositae. 



Ligule, (1) a small membranous appendage at the summit of the sheath of grass- 

 leaves; (2) the one-sided limb of the corolla in many Compositae. 



Limb, the upper lobed and usually spreading part of a calyx or corolla; it is an 

 expansion upwards of the tube or united part of the calyx or corolla. 



Li/near, long and narrow, with parallel edges. 



Lobe, division of a leaf reaching about half-way to the midrib, or of some other 

 organ which is only divided for about half its length. 



Lobed, (1) cut about half-way; (2) a compound ovary or fruit which is deeply 

 grooved between the carpels. 



Locu icidal, when a ripe capsule splits open along the back of its cells (i.e., along 

 the dorsal suture or midrib of the carpels), as in Juncaceae and most 

 Liliaceae. 



Lunate, crescent-shaped. 



Lyrate, a pinnatifid or pinnatisect leaf with a terminal lobe much larger than the 

 lateral ones. 



Mealy (farinose) , covered with a scurfy powder like flour. 



Membranous, thin, transparent and flexible, not green. 



Mesocarp, the second or middle layer of the pericarp; it is often succulent and 

 is then sometimes called the sarcocarp. 



Micropyle, a minute opening in the coats of the ovule. In the great majority 

 of plants the pollen-grain finds its way to the embryo-sac through the 

 micropyle. 



Midrib, the central nerve of a leaf. 



Moniliform, when a pod or other organ is constricted at regular intervals, so as 

 to resemble a necklace of beads. 



Monoecious, a plant which has the male and female flowers on the same individual. 



Mucronate, terminating abruptly in a short stiff point called a mucro. 



Muricate, covered with short hard points. 



Naked, flower without any perianth; seed without a pericarp. 



Nerves (veins), the vascular bundles which start from the petiole and traverse the 

 blade of the leaf, the smaller ones often forming a network. 



Node, the swollen part of the stem from which leaves or branches spring. 



Nut. — Properly a 1 -seeded indehiseent fruit, such as the hazel-nut, with a hard 

 dry pericarp ("shell"), but also used to describe any hard 1-seeded 

 nutlike fruit, such as those of Polygonaceae and Cyperaceae. 

 Obcordate, inversely heart-shaped, broad, and rather deeply notched at the 

 summit. 



Oblanceolate, lanceolate with the narrow end at the base of the leaf. 

 Oblique, slanting; (of a leaf) unequal-sided. 



