CATALOGUE. 191 



Gentiana* humilis, Stev. Griseb. in DC. Prod. 9, 106. Engelm. 

 Trans. Acad. St Louis, 2, pi. 9, figs. 1-5. Gray, Syn. 120. — Biennial, with 

 large, broadly oval, rosulate, white-margined basal leaves, and few or many 

 ascending stems of a pale yellowish-green; cauline leaves small, linear- 

 oblong; flowers single, terminal; corolla greenish or whitish, 4-6" long, 

 tubular, with acute lobes, and short, notched folds; anthers oval, introrse; 

 capsule clavate-obovate, on a long stipe, usually much exceeding the corolla; 

 seeds oblong. 



Wet, grassy spots in the higher Rocky Mountains ; also in Asia. 

 The long, protruding capsules (trumpet-shaped when open), together 

 with its pale, sickly look, give the little plant a very curious ap- 

 pearance. 



Gentiana peosteata, Heenke ; Griseb. I. c. Engelm. I. c. figs. 9-14. 

 Gray, Syn. 120. — Annual, small, weak, 1-2' high, with horizontal or decum- 

 bent branches ; leaves only 2-3" long, ovate, green with narrow white 

 margins; flowers azure-blue, 4-parted, terminal- on the branches, 5-6" long 

 (or in luxuriant specimens sometimes larger); lobes ovate-lanceolate; 

 appendages half as long, similar or sometimes notched; anthers oval, 



* The presence or absence of folds or plaits between the lobes of the corolla and the mode of 

 attachment of the anthers to the filament separate the Ge ntians into two large and very natural sec- 

 tions, already recognized by old authors: Gentianella (Borkhausen), Gray, has a corolla without folds and 

 the anthers versatile; Pneumonanthe (Necker), Gray, has a corolla with folds between the lobes and fixed 

 anthers. It will not be useless to explain the term versatile in respect to anthers, as many seem to mis- 

 understand it, so that they speak of versatile anthers as accidental and unconnected with a physio- 

 logical process. The fact is that in Gentianella the anthers are introrse in the bud and after it firstopens; 

 but as soon as the flower is fully expanded (generally toward the middle of the day) the anthers gradu- 

 ally assume a horizontal position (the notched base raised and turned toward the as yet immature and 

 closed stigma), open the cells upward, and begin to shed their pollen. Toward evening, the now effete 

 anther is turned over backward, and on the next morniug we find it hanging on the back of the fila- 

 ment, the notched lower end turned up and the empty cells directed outward. Thus in about twelve 

 hours it has described «tn almost complete circle. In my figures of Gentians in the Transactions of the 

 Academy of Saint Louis, vol. 2, pi. 7, 8, 9, and 11, versatile anthers are erroneously represented as turn- 

 ing indiscriminately outward or inward. This is a mistake, as the above account of the living action of 

 the anthers shows. In the figures of G. humilis and prostrata, pi. 9, the anthers are also figured as ver- 

 satile in that unnatural manner, while in these species they are constantly erect and introrse, as well 

 before opening as when effete. 



In Pneumonanthe the anthers remain fixed in two forms. In one section, comprising mostly smaller 

 plants, with smaller flowers (G. prostrata, verna, Altaica, humilis, utriculosa, etc.), they are introrse. In 

 another section, the true perennial large-flowered Pneumonanthes, to which we must add also an annual, 

 G. Douglasiana, and the European G. cruciata, they are extrorse. In the genera Halenia, Pleurogyne, 

 Swertia, and Frasera, all represented by plants collected in these expeditions, we find the same arrange- 

 ment of versatile anthers as in Gentianella. It therefore seems proper to enumerate, first, the Gentians 

 with fixed anthers, and next those with versatile anthers, and then, joining them, the other genera with 

 similar versatile antheral arrangement. 



