On the Gen us Achlys. A Morphological and Systematic Study. By Hisayoshi 'l'akecla, n. I. C. Lately Demonstrator of Botany, Royal College of Science, London. With Plate VII and ,l text}igui·es. Achlys, a small genus of Berberidaceae, was founded in 1821 by DE CANDOLLE (5, p. 35) for a North American plant previously known as Leontice triphylla Sl\1. (16, no. 5), This monotypic genus was enriched by MAXIMOWICZ(13) in 1867, who described a second species, A. japonica. Ten years later, T. ITo, when working out the Japanese Berbericlaceae at Kew, reduced this second species into the former, regarding it as a mere variety (11, p. 435). The Japanese plant may, however, be discerned as a distinct species 1>, hence the genus includes, at present, two closely related species. When establishing this genus, DE CANDOLLEhad only an imperfect specimen in SMITH'S herbarium at his disposal, aucl, as a result, his description 2l of the floral structure is very un- satisfactory. One of the remarkable points in DE CANDOLLE's account is that he describes the presence of numerous petals, which was positively denied by SMITH (16, no. 5). Little was known about this genus before 182H when Sir WILLIAM J. HOOKER published a very detailed de:-cription of A. triphylla, which was accompanied by a beautiful plate ( 10, p. 1) The rearnns are given below (p. 180). 2) 'Calyx ...... Petala co minima linearia fere rnbulata. Hamiua filamenti;; 1 lanius· culis basi attenuatis apice dilatatis, antherac loCcuiis valdil descrctis rirnt, trnnsvt>rsali dihi;centibus.' 170 '1.'J-IEBO'L'ANIOAL llfAGAZINE. [Vol. XXIX. No. 341\. 30, tab. 12). HooKER points out that there is no trace of perianth, and that 'what DE CANDOLLEtook for petals ...... must have been stamens, from which the anthers had fallen.' Unfortunately, both the description and figures given by HooKER are inaccurate in certain respects especially with regard to the floral mechanism. BENTHAM workiug out the family Berberidaceae for the Genera Plantarum had ample material for examination, and was able to give a better diagnosis of the genus (2, p. 45). He was the first to make out the arrangcmen t of .stamens 1\ and to furnish a short description of the fruit 21• BAILLON in 1872, ten years after the publication of the Genera Plantarum, states that there are 6-12 stamens in a single flower (1, pp. 61, 66). In the same year the true nature of fruit of Achlys was very accurately described by ASA GRAY (7, p. 376). He points out that the fruit is 'certainly. not " bivalvatim dchiscens " nor dehiscent at all'. He also rightly compares the ventral fleshy ridge of fruit with the thickened placenta of Podophyllum, since that structure is, as a matter of fact, the ventral suture of the ovary. In 1876, BREWER and WATSON (3, pp. 15-16) described the genus most accurately except for some points regarding the stamens 3l. In 1888 there appeared CALLONI's paper on the genus Achlys ( 4), in which the author gives a detailed account of the evolution of the leaf, and of the morphology of the perigone and the ~tamen. CALLONI gives an accurate description and figures of the stamens ( 4, p. 31, tab. ix, figs. 15-21 ), and also states that the andrrecium of Achlys consists of 6, or more frequently 9 stamens. He also points out ( 4, p. 31) that HooKER's descrip- tion of the anther is erroneous, since the anther of Achlys is comparable with that of Berberis, Epimedium and Leontice. 1) 'Stamina (a.n semper ?) 9, 3-serialia.' 2) 'Capsula parva (dorso bivalva.tim dehiscens ?) .' 3) 'Stamens 9, in 3 row~; filaments slender, the outer dilated at the mmmit; anthers short'. JI TAIOWA.-ON 'l'lIB C/ENUS A.OHLYS. 171 CALLONI's discovery of a rudimentary perigone ( 4, p. 30, tab. ix, figs. 13-14) is remarkable, since the presence of a perirrnth in Ach~vs had been denied by all the previous workers except DE CANDOLLE who mistook old stamens for this structure. In 1895 AsA GRAY (8, p. 67), apparently influenced by the papers of HooKER, BAILLON, and BREWER and WATSON, gives '6-12' as to the number of stamens and repeats some other mistakes in connection with the morphology of stamens. TISCHLER in his paper on Berberidaceae and Podophyllaceae published in 1902 states (18, p. 6Sl) that he found only six stamens in the flo,vers which he examined. With regard to the debiscence of the anther he alludes to CALLONI's work and maintains the view thut the anther shows a trnmition to a 4-valvular dehiscence such as is seen in Berberis quinduensis. It is singular thn t TrsCHLER 1l again regards the fruit as a capsule (18, pp. 682, 723). From the above sum- mary of all previous con- tributions to the know- ledge of this genus, one can perceive that very little is known of this genus, and also that there are differ- ences of opinion especially with regard to the mor- phology of the stamen. The writer has had an Text-fig. T. opportunity of studying Acltlys triphylla DC. x 14,;. Achlys japonica from fresh 1) And also CrrnRNE (cf. 18, p. 713). 172 'l'TTR TJO'l'ANTOAT, llfAGAZlNFJ. [Vol. XXIX, No. 3-111. material collected near Satporo during 1907-1909 and has therefore been able to overcome certain difficulties in connection with the elucidation of the floral mechanism. His study of the genus has also been greatly facilitated by an examination of ample material of dried specimens of A. triphylla preserved in the herbaria of Kew, the British Museum nnd Edinburgh. In the following pages a foll description of the genus followed by a discussion of the morphological nature of certain organs and of the systematic position of the genus is given. Since both the North American and the Japanese species are very similar, they will be considered collectively except for certain points of specific difference. The Leaf. One leaf is produced to a flower-bearing shoot in each season from the terminal bud of a sympodial rhizome. Th~ leaf is provided with a long, slender petiole which stands upright from the ground, and in a luxuriant specimen of A. triphylla measures as much as 52 cm. in length. As a rule the lamina consists of three sessile lenflets, but in abnormal specimens two or four leaflets may occui-. In a small specimen it measures only a few cm. in oiameter, but in a very luxuriant specimen of A. triphylla a diameter of 30 cm. is reachedn. The terminal leaflet is rhomboid-obovate to broadly rhom- boid-obovate and is shallowly trilobed at the apex (text-figs. II, 2, 5, III, 1-5). In wcll-devoloped specimens of A. triph_vlla each of the three lobes again produces one or two lobes, resulting in the formation of five to nine larger or smaller triangular lobes (text-fig. I). In A. _japonica, on the other hand, the sini become much deeper, thereby producing three oblong segment~, the cen- tral one of which may again be trilobed (text-fig. II, 1, 3, 4) 2l. The lateral leaflets are very broadly cuneate and inequi- lateral. The outer margin is unequally sinuate-dentate or irre- 1) In A. ,i,ipon-icathe diameter of the lamina never exceeds 20 cm. 2) In rare cases the terminal leaflet may become quadrilobed, but not more, as in A. ti·iphy/la. Oct., -191,5.} ll. 1'AKEDA.-VN 1'HE GENUS AOHLYS. 17,3 -gularly lobed, or m some cases, particularly in A. japonica, it may be slightly undulate or even almost entire (e. g. text-fig. II, 2). tn luxuriant specimens of A. triphylla the teeth are increased in number, and sometimes more than ten are present, but they remain deltoid in shape and do not be~ come oblong lobes. In A. japonica, on the other hand, the teeth of the lateral leaflet,s often show a tendency to decrease in number and to become oblong lobes by deep incision. Text-fig. JI. Text-fig. II, 1, 3 and 4 Achly-~ japo•nica MAXIM. xT+,,. show such a deepening of a sinus, and, in one of the leaflets in 1, it has resulted in the formation of an extra leaflet. Although in extreme forms of these two species the incision of the leaflets is quite different, yet on the whole the shape and dimension of the leaf are of little use for diagnostic purposes. The Inflorescence. The inflorescence terminates the stem which forms an upright scape, very similar to the petiole but usually taller. Flowers are densely clustered together in a spike 2-5 cm. in length, which is terminated by a perfect flower. The spike is continuous in A. triphylla, but is more or less interrupted in A. japonica as MAXIMOWICZ correctly describes (14). HOOKER (10, p. 30) 174 THK ROTANIOAI, MAGA7,JNE. [Vol. XXIX, No. 34r,, and !To(11, p. 436) on the other hand state that the spike of A. triph_ylla is interrupted. This statement is certainly incorrect. When young, the spike appears to be looser near the base and much more compact towards the apex. This is due to the fact that the apical region is much younger than the basal part. HooKER's figure (10, tab. 12) shows a few of the basal, more mature flowers widely separated from the rest, but this is really due to exaggeration on the part of the delineator and is very misleading. In A. iaponica the spikes are, as a rule, in- terrupted particular- ly m their basal region, a few small groups of flowers being distantly dis- posed on the rhach is.