PHANEROGAMIA 567 



diplostemonous ; ovary usually without distinctly differentiated 

 ovules or placenta. Leafy shrubs parasitic on trees (Fig. 544). 



The plants of this family are mostly tropical. Loranthus europaeus occurs 

 upon Oaks in Eastern Europe. Viscum album, the European Mistletoe, is a small 

 evergreen, dichotomously branching shrub, parasitic upon various species of trees. 

 It absorbs its nourishment by means of haustoria consisting of root-like strands 

 concealed between the cortex and wood of the host-branch. The white berries 

 produced by the female plants are eaten by birds, which in freeing their bills of the 

 sticky endocarp, by wiping them on the bark of trees, are at the same time instru- 

 mental in distributing the seeds. 



Poisonous. — The berries of Viscum album when eaten by children have been 

 known to produce symptoms of poisoning. 



B. Sympetalae 



Perianth consisting of a calyx and an almost always sympetalous 

 corolla. 



The flowers are always cyclic, and in the majority of cases con- 

 structed, actually or theoretically, according to the formula K5, 

 C(5), A5, G(2). The stamens are generally inserted on the 

 COROLLA. The fact that the gyncecium consists typically of only two 

 carpels, must be regarded as the result of reduction, as flowers with 

 five carpels sometimes occur. To the Sympetalae belong the following 

 orders : Ericinae, Diospyrinae, Prirnulinae, Contortae, Tubiflorae, Person- 

 atae, Labiatiflorae, Bubiinae, Campanulinae, Aggregatae. 



Order 1. Ericinae 



Flowers usually hypogynous, actinomorphic ; formula, Kn, Cn, 

 A2n, G(n), in which n is usually 5 ; corolla sometimes choripetalous ; 

 androecium obdiplostemonous, not adnate to the corolla ; pollen 

 usually in tetrads; ovary multilocular. Leaves needle-shaped or 

 lanceolate. 



Of all the Sympetalae the Ericinae approach most closely the 

 Charipetalae, not unfrequently having free petals, while the stamens are 

 inserted directly on the receptacle. They form a very natural group, 

 whose close affinity is exhibited, not only in the structure of the 

 flowers, but also in the vegetative organs. The axes are nearly 

 always woody, usually comparatively short, and branching profusely 

 close to the ground. The leaves are generally small and entire, in 

 most cases leathery and evergreen. The flowers are always adapted 

 to insect-pollination ; they are often quite small, but in that case are 

 aggregated in conspicuous racemes, usually of a white or crimson 

 colour. The seeds are small. 



