The column is the most characteristic part of an orchid flower. It is considered to be formed by the union of stamens with a central style and stigma. In the Apo- stasieae, for example, the column is rather primitive in the stamens and style only partially united, whereas in the majority of higher orchids it becomes more advanced through a eomplete union of them into a single organ. Within the family, indeed, the column structure is greatly diversified and of great taxonomic significance. It is interesting to note that a great range of diversity of column structure is bund in Neottia (sensu lato), a small but widespread genus consisting of 14 species, about two thirds of which, however, are of local occurance and seem to be little known to many botanists. In some speeies of this genus we find a very primitive column structure which is quite unique in the family, while in the others it is much more complicated. In all, five types of their column structure can be distinguished as fol- lows: (1) column rather longer; anther erect with a short filament attached to the back of the column near the apex; stigma terminal; neither clinandrium nor rostel- lure; (f. 2, 4) (2) as the preceding, 'except for the stigma more or less curved fore- ward and filament longer; (f. 6, 8) (3) column rather longer with a clinandrium at its summit, upon which a sessile and incumbent anther sits; rostellum large, hori- zontally projecting out over the concave stigma situated in the front of the column; (f. 10, 13, 15, 17) (4) as the preceding, except, for the anther and rostellum almost erect, and the stigma more or less bilabiate; (f. 19,21) (5) column very short; an- ther and rostellum erect; stigma lamellate, erect; reflexed and almost clasping the rostellum. (f.,2g) In these .five types, with the exception of the first one in which the labellum (the median petal) is very similar to the lateral: petals, they all possess zygomorphic perianth with labellum bilobed or entire which is quite different from the two lateral petals. Here, we see a great change in the column structure from one form with stamen and style not fully united to another form in which they have been well fused. Speaking strictly, these are two sorts of entirely different column structure. The former one, represented by (1) and (2) as stated above, is, in fact, an incomplete or s very primitive column in having a terminal stigma and an erect stamen with its free filament attached to the back of the column; and the absence of clinandrium and rostellum. Furthermore, there exists on the back of the column a thick ridge with its upper end joined to the filament, with which it is of the same texture and appearance. In Neottia pantlingii (=Arohineottia pantlingii) the free filament is even rather longer than the ridge, (f. 6) while in the other three species (f. 2, 4, 8) they are shorter. It is in my opinion the lower part of the filament adnate to the compound style or column. This is another fact of interest perhaps not occuring in any other living orchids. On the other hand, the latter one, represented by (3), (4) and (5), is a more advanced column structure, in which a higher level of specialisa- tion with well-developed clinandrium and rostellum is reached. The stigma becomes shallow depressed on the anterior side of the column, or sometimes in the form of so- mewhat a bilabiate lip projecting out before or under the long rostellum. This is apparently a complete column both in structure and function quite different from the former and, contrarily, much like that of Listera. Basing upon the facts just mentioned, we may subdivided Neottia (sensu lato) into two distinct genera, with two and three sections respectively. They are as fol- lows: 1. Archineottia S. C. Chen, gen. nov. (1) Sect. Archineottia 1) A. gaudissartii (Hand.-Mzt.) S. C. Chen, comb. nov. (China) 2) A. microglottis (Duthie) S. C. Chen, comb. nov. (India) (2) Sect. Furciila S. C. Chen, sect. nov. 3) A. pantlingii (W. W. Smith) S. C. Chen, comb. nov. (Sikkim) 4) A. smithiana (Schltr.) S. C. Chen, comb. nov. (China) 2. Neottia Guett. (1) Sect. Listeroides S.C. Chen, sect. nov. 1) N. listeroides (L.) Rchb. f. (China, Sikkim, Kashmir) 2) N. camtschatea (L.) Rchb. f, (China, Soviet Union) 3) N. megalochila S. C. Chen, nom. nov. (China) 4) N. inayatii (I)uthie) Schltr. (Pakistan, Kashmir) 5) N. tenii Schltr; (China) (2) Sect. Neottia 6) N. papilligera Schltr. (Chinas: Japan, Korea, Soviet Union, Sikkim) 7) N. nidus-avis (L.) L. C. Rich. (Europe, Iran, Western Siberia) 8) N. brevilabris Tang et Wang: (China) (3) Sect. Hologlossa S. C. Chen, sect. nov. 9) N. acuminata Schltr. (China, Japan, Korea, Soviet Union, Sikkim) Inperfeetly known species: 10) N. ussuriensis (Kom. et Nevski) S6o (Soviet Union) Thus, the subtribe Neottiinae are composed of four genera, namely, Diplandror-
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