GLOSSARY OF BOTANICAL TERMS 315 



Honey, or Nectar, the substance secreted by many flowers to 



attract insects. 

 Honey-glands, the organs which secrete honey. 

 Humus, decomposing organic matter in the soil (pp. 119, 143). 

 Hybrid, a cross between two species or races (p. 70). 

 Hypogynous, applied to flowers in which the calyx and corolla arise 



directly from the receptacle and in which the ovary is superior. 

 Imbricated, overlapping, like the tiles on a roof. 

 Indehiscent, applied to fruits which do not open to allow the 



seeds to escape ; cf. Dehiscent. 

 Inferior, applied to the ovaries of those flowers in which the 



calyx tube encloses the ovary, as in epigynous and some 



perigynous flowers ; cf. Superior. 

 Inflorescence, the mode of branching of the floral axis; the 



manner in which the flowers are arranged on the primary 



and lateral shoots. 

 Insectivorous, applied to plants which capture insects and 



absorb nutriment from them. 

 Intemode, the portion of the axis between the insertion of two 



successive leaves (p. 191). 

 Introrse, applied to stamens in which the anthers open inwards, 



towards the centre of the flower. 

 Involucre, the whorl or rosette of bracts below an inflorescence 



or a single flower (see pp. 35, 111). 

 Irregular = Zygomorphic {q.v.). 

 Keel, a term applied to the two lower, united petals of the 



flowers of members of the Leguminosas. 

 Labellum, or LoTver Lip, applied to the enlarged and 



irregularly shaped member of the inner whorl of perianth 



members in the Orchids (p. 137), and to a similarly placed 



petal in other flowers. 

 Lamina, the blade of a leaf. 

 Lichens, a group of thaUoid plants, consisting of Algae 



associated with Fungi (see p. 291). 



