528 PICOTYLEDONES. 



Primulacese). For tlie rest the flower is distinctly bilabiate, both 

 in the calyx and corolla. Two-valved capsule ; no endosperm. 



Pingnicula (Butter-wort) has a rosette of leaves close to the 

 ground ; these ar-e sticky, covered with glandular hairs, and roll 

 round any small insects which may be caught upon them ; flowers 

 solitary, terminal on a long scape; calyx, 5-partite ; corolla with 

 spur. The embryo germinates with 1 cotyledon. Utricularia 

 (Bladder- wort). Our native species are floating, without roots, 

 with hair-like, divided leaves, studded with peculiar bladders (in 

 the Tropics there are terrestrial species, with ordinary foliage). 

 The bladders (Fig. 569) have an aperture, closed by a valve open- 

 ing inwards, so that small aquatic animals are allowed to enter, but 

 are not able to escape; they are thus entrapped in the bladders, 

 and are probably used as food. Calyx bipartite ; corolla personate 

 with spur. 



The embryo of Utricularia is very imperfect, scarcely more than a spherical, 

 cellular mass, with a few slight leaf-rudiments. Oil the germination of U. 

 vulyaris, several bristle-like leaves develop into a compact rosette ; the stem 

 then develops, and also the finely-divided, bladder-bearing leaves. A primary 

 root is not developed. The stems branch copiously and in a very peculiar 

 manner. The growing-point of the stem is rolled spirally. The stigmatic lobes 

 are sensitive aud close on being touched; self-pollination often takes place, 

 however, in Pinguicula. 



Order 5. Gesneriaceae. The flower in this order may be both efiiyynaiis 

 (Gesneriece) and hypogynous (Cyrtandreee), but otherwise is nearly the same as in 

 Scrophulariaceae, only that the ovary is unilocular, viiih2 parietal, often bifid, pla- 

 centce. Of the 5 stamens the posterior is rudimentary, or (more rarely) entirely 

 wanting, and the others are didynamous (Cyrtandrese have often only 2 stamens) ; 

 their anthers are generally glued into a quadrangular mass. The majority are 

 herbs with juicy stems, opposite, verticillate or scattered leaves without stipules, 

 often, like the stems, thick and juicy, soft-haired or glabrous. The corollas 

 are often highly-coloured (scarlet, red-yellow, etc., and spotted internally), large 

 and magnificent, so that many species are ornamental plants. GESNEHIE.E 

 (often epigynous) have eudospeim ; S. Am. CI'HTANDRE;E, hypogynous, with- 

 out endosperm ; Asia, S. Africa. Streptocarpus, neither the primary root nor 

 primary shoot attains development ; one of the cotyledons dies, while the other 

 grows and becomes a very large foliage-leaf, from which spring adventitious 

 roots and adventitious inflorescences. 



500 species. Gloxinia, Achimenes, Gesneria, Alloplectus, Tychea, Columnea, 

 NtzgeUa, jEsahynanthus, and others, especially in the forests of tropical 

 America. Some are epiphjtes on trees, others prefer the leaf-mould of the 

 forest and crevices of cliffs. Several genera have peculiar, catkin-like, under- 

 ground shoots, with scale-like compact leaves ; others have tubers. 



Orobanche (Broom -rape) is allied to this order as a parasitic form. It is a 

 parasite on the roots of other plants, not like Lathrcea by means of thin root- 



