. British plants; their biology and ecology. Botany; Botany; Plant ecology. 172 BRITISH PLANTS into three classes, based upon the availability of the honey : 1. Those with freely-exposed honey, which may be visited by all kinds of insects, even those with the shortest tongues (flies, beetles, short-tongued bees, wasps)—, saxifrages, gahum, ivy, most of the Umbelliferse, bar- berry, hedge - mustard, spindle-tree. Many of these flowers are small, but their conspicuousness is increased by the massing of them together (see paragraph on in- florescences, p. 178), or they make their presence evi
. British plants; their biology and ecology. Botany; Botany; Plant ecology. 172 BRITISH PLANTS into three classes, based upon the availability of the honey : 1. Those with freely-exposed honey, which may be visited by all kinds of insects, even those with the shortest tongues (flies, beetles, short-tongued bees, wasps)—, saxifrages, gahum, ivy, most of the Umbelliferse, bar- berry, hedge - mustard, spindle-tree. Many of these flowers are small, but their conspicuousness is increased by the massing of them together (see paragraph on in- florescences, p. 178), or they make their presence evident by a strong scent. Short-tongued insects are not efficient pollinators, because they seldom confine their attention to one species of flower. Such flowers are also more. Fig. 72.—Christmas Rose (HeUeborus). 1, longitudinal section of flower: a, honey-leaf; 6, carpels; c, stamens; d, sepals ; e, receptacle. 2, honey-loaf, enlarged. exposed than others to insects which rob them of honey, but are useless in effecting pollination. They are also liable to have their honey spoiled by rain. 2. Flowers with half-concealed honey. These are, evolutionaUy, flowers of a higher type than Class 1. Their honey lies deeper, and is more difficult to get at. It is more protected from rain, and is less exposed to the ravages of unwelcome guests—, buttercup, stonecrop, many Crucifers, potentil, etc. Th^re is every gradation between the flowers of this class and the preceding. The insects have tongues between 2 and 3 lines long (a line is Y? inch). They are mostly short-tongued bees and the longer-tongued flies. Among the unbidden guests of flowers are the wingless and crawling insects—, ants. They enter the flower on foot, but before the honey is reached the path is often stopped by viscid secretions on. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations m
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectbotany, bookyear1920
