1917-18. J BOTANICAL SOCIETY OF EDINBURGH 247 



but only one species — G. hexa'phylla, Francli. — is in cultiva- 

 tion so far as I know. Introduced by Farrer, it flowered 

 at Edinburgh in August 1916, in plants raised from seed 

 presented by the late Robert Woodward, Esq., jun., of Arley 

 Castle, Bewdley. 



In the paired-leaved series of which I write, the leaves 

 of the pair have each the potentiality to produce an axil- 

 lary shoot, but as so commonly happens in such cases the 

 bud of one of the leaves is prepotent, and the prepotent 

 buds in successive pairs follow a \ spiral course round the 

 axis which produces them. If a prepotent bud develops 

 a shoot, its sister bud in the ojjposite leaf -axil is suppressed, 

 but if from any cause the prepotent bud be arrested or 

 destroyed, then the energies of the sister bud are called 

 upon and it may elongate as a shoot. Thus each stolon 

 has capacity to branch — a double chance from each node — 

 and these branches, each of them, has, like the mother stolon, 

 the power to root at the nodes and to end in one flower. 

 The vegetative and reproductive capabilities of the plant 

 are therefore great. G. Farreri, G. Laivrencei, and G. sino- 

 ornata exhibit this stolon-branching to the greatest extent 

 — G. Veitchiorum in my experience the least. And this 

 seems to be constitutional. For the former are the most 

 satisfactory of plants, and the flexibility of their parts lends 

 them to the most ordinary of handling. On the other hand, 

 G. Veitchiorum seems to be, at Edinburgh, a less adaptable 

 plant — stifl'er, less ready to respond. 



In the solitary terminal flowers the calyx has an entire 

 tube with long distinct lobes. By entire I should perhaps 

 explain that the tube of the calyx is not split down one 

 side as it is, for instance, in G. decumhens — to name a well- 

 kuown garden plant. The distinction is an important one 

 for differentiation of species of Gentian. The corolla, large 

 and showy, some 5-6 cm. long, obconoid and funnel-shaped, 

 sometimes slightly bulged above the calj^x, is of various 

 shades of blue, and has broad paler striped or suffused 

 petaline bands on the outside. The folds, though toothed, 

 are never fringed. The ovary has a long stalk, and the 

 style is also long, with the branches recircinate at the tip. 



These Gentians grow at Edinburgh in any good moist 

 garden soil, either in shade or in full sun exposure — ffower- 



TEANS. BOX. SOC. EDIN. VOL. XXVH. ] 8 



