TUBIFLORJ;. 515 



ovary is found a yellowish ring-like nectary (Fig. 552 C), sometimes 

 5-sinuate or 5-partite. The leaves are nearly always scattered ; 

 stipules are absent. The Solanacese, which formerly were classed here, are 

 so closely allied to the Personatse, that it would be unnatural not to place them 

 first in this family ; and the Boraginaceee (which were also placed in the 

 Tubifloras) appear to be best united, with the Labiatse and others, into one family 

 Nuculiferae. 



Order 1. Polemoniaceae. The flowers are regular ; S5, P5, A5, G3. The 

 calyx and corolla have united leaves, the petals tioisted to the right in (estiva- 

 tion (all the left edges being covered). The ovary is 3-locular with 2-oo ovules in 

 each loculus ; the style is trifid at the apex ; the fruit is a 3-valved capsule. 

 Embryo straight; endosperm fleshy. The inflorescences are dichasia passing 

 over into unipared helicoid cymes (the shoot of the loiver bracteole being the 

 more strongly developed). Herbs without latex. 150 species ; especially 

 Western N. Am. Phlox (salver-shaped corolla ; entire, opposite leaves), Pole- 

 monium (campanulate or almost rotate corolla; scattered, pinnate leaves), 

 Leptosiphon, Gilia, Collomia, Cobcea (climbing, like the Vetches, by tendrils at 

 the ends of the leaves), etc. They are frequently ornamental plants. 



Order 2. Hydrophyllacese. This order approaches very closely to the 

 Boraginaceae. Herbs with pinnate or palmate leaves; S5, P5, A5, G2 

 The lobes of the corolla are imbricate in aestivation. Generally 2 median 

 carpels. The ovary is most freqiiently unilocular, and the seeds are situated 

 on 2 parietal placenta; capsule 2-valved ; embryo straight ; endosperm fleshy. 

 In the corolla-tube, opposite the corolla-lobes, there are frequently append- 

 ages of various forms, which resemble those of Cuscuta. The inflorescences 

 correspond exactly with those of the Boraginaceas, being unipared scorpioid 

 cymes, which, prior to opening, are tightly rolled up. 130 species, especially 

 in N. Am. (California, etc.). Many annual species of Phacelia, Nemophila, 

 Whitlavia, Entoca, Cosmanthus, etc., are cultivated in gardens as ornamental 

 plants. Hydrolea (has a bilocular ovary, and two free styles). 



Order 3. Convolvulacese (Bindweeds). The flower is regu- 

 lar, hypogynous, with 5 almost free sepals (quincuncial aestivation), 

 P5, A5, G2 (rarely 3-5). The corolla is very characteristic; it 

 is (with various forms) almost entire, or slightly 5-lobed, and 

 folded longitudinally in the bud in such a way that 5 projecting, 

 flat portions, tapering towards the top and frequently differing in 

 colour and hairiness from the rest, are visible externally and 

 applied close together, while the remainder of the corolla is folded 

 inwards (Fig. 552 A) ; and hence the whole corolla is strongly 

 twisted to the right in the bud. The gynoeceum most frequently has 

 a bilocular ovary; in each loculus there are only 2 (erect) anatropous 

 ovules on the placenta, which is not especially thickened (Fig. 552 

 D, E) ; each loculus is sometimes divided into two by a false septum 

 (a relationship with the Boraginacece, etc.); style simple with 



