. A textbook of botany for colleges and universities ... Botany. 840 ECOLOGY with flowers; this habit is without obvious advantage, though it has been suggested that trunk flowers are well protected from torrential rains. Cauliflory appears to be stimulated by an excess of moisture; it has been induced in the grape also by wounding and in the orange by defoliation. In some tropical trees and shrubs (as in Ficus geocarpa) flowers break through the soil from subterranean stems. Tran- sitions between wind-pollinated and insect-pollinated flowers sometimes are seen, as in the ericads, where the po
. A textbook of botany for colleges and universities ... Botany. 840 ECOLOGY with flowers; this habit is without obvious advantage, though it has been suggested that trunk flowers are well protected from torrential rains. Cauliflory appears to be stimulated by an excess of moisture; it has been induced in the grape also by wounding and in the orange by defoliation. In some tropical trees and shrubs (as in Ficus geocarpa) flowers break through the soil from subterranean stems. Tran- sitions between wind-pollinated and insect-pollinated flowers sometimes are seen, as in the ericads, where the pollen which commonly is scattered by insects ultimately becomes dry and powdery and thus may be scattered by the wind; chestnut flowers which usually are wind-pollinated are fragrant and attract insects. Ephedra cam- pylopoda is interesting as be- ing an insect-pollinated gym- nosperm, the flowers, which are much frequented by in- sects, exhibiting nectar and sticky pollen which coheres in masses. Before consider- ing in detail the features that attract insects to flowers, it is necessary to consider the pollinating organisms themselves. Pollinating insects. — General remarks. — The vast majority of efficient Figs. 1166-1169. —Flowers of Salvia, illustrating pollinating animals are pollination by bees: 1166, a flower of 5ofojagto!»0io in jjjggj^j-g particularly flv- longitudinal section, the arrow indicating the direction ' ^ J J taken by visiting bees; s, style; a, anther; 1167, a simi- lar section, showing the lower arm of the connective lever pushed back, as by an entering bee, the pollen- bearing anther {a) thus being deflexed in such a way as to rub pollen over the insect; 1168, a Salvia flower into which a bee has entered, the anther (o) being in contact with the bee; 1169, an older flower, showing the stigma (g) in such a position as to come into contact with an entering bee; 116S and 1169 show that Salvia is protan- drous. — 1166 and 1167 from Kerner; 1168 and 1
Size: 1717px × 1455px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1910
