202 GLOSSARY 
Involucre—A. whorl of bracts beneath a flower or an inflorescence. 
Irregular (of a flower)—Where the petals are not all alike. 
Labellum (in Orchideze)—One of the petals which is usually much 
larger than the others. 
Latex—A milky juice formed in special receptacles (Papaver, Son- 
chus, Euphorbia). 
Legume—A dehiscent seed-vessel splitting down both back and 
front (Leguminos@). 
Ligule (in grasses)—A small appendage to the leaf at the point 
where it springs from the stem. 
Loculus—A division or chamber of the ovary. 
Maile (of flowers)—Having stamens but no pistil. 
Mericarp—Each half of a cremocarp (Umbelizfere). 
Monadelphous (of stamens)—The filaments all more or less cohe- 
rent (Leguminos@). 
Monectous—Having male and female flowers on the same indivi- 
dual (/aze/). 
Mucronate (of leaves)—When the mid-rib projects beyond the leaf 
like a tooth. 
Nectary—Any organ that secretes nectar. 
Node (of stems)—The zone from which one or more leaves spring. 
Nutlet—A small dry indehiscent fruit (Borraginee). 
Ochrea—A stipule-like structure forming a sheath round the stem 
(Polygonace@). 
Ovary—The lower part of the pistil containing the ovules. 
Ovule—A rudimentary seed. 
Pale (in grasses)—An inner bract, from the axil of which springs a 
flower. 
Panicle—A branched raceme (Gramine@). 
Pappus—The crest of silky hairs into which the calyx is sometimes 
transformed (Composite). 
Parasite—A plant which obtains its sustenance from the living 
tissues of another plant (Dodder, Mistletoe). 
