The column types of Neottia and Archineottia of the family Orchidaceae and their taxonomic and phylogenetic significance

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 Apostasieae, 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 rostellure; (f. 2, 4) (2) as the preceding, 'except for the stigma more or less curved foreward 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, horizontally 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; anther 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 specialisation 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 somewhat 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 follows: 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, Diplandrorchis, Archineottia, Neottia and Listera. The new genus Archineottia, as one of the most primitive genera in the family, is of great interest from a phylogenetic point of view. It shows dose similarity to Diplandrorchis and Neottia in habit, but sharply distinct from them in column structure. These genera, as indicated By some authors, also show affinity in some respects with the subtribe Limodorinae, especially to Tangtsinia and Sinorchis, the other two quite primitive genera in the family. There is, indeed, a great need of further study of these interesting or relic genera and this, I think, would go a long way towards solving the problems concerning the origin ofthe Orchidaceae.     

Floral morphology and ontogeny in Orchidaceae subtribe Disinae

Floral morphology and ontogeny in Orchidaceae subtribe Disinae. The flower structure and development of 24 species of the orchid subtribe Disinae are described and illustrated by drawings and scanning electron micrographs with special attention being paid to the gynostemium. The morphogenesis of this subtribe is fundamentally similar to that of the closely related tribe Orchideae. This includes the initiation of the auricles on the anther base in a dorsolateral position, and hence their interpretation as being mere appendages of the filament. The keel connecting the petals and the gynostemium plus its protrusion is considered homologous to the inner lateral staminodeS. Presumed vestiges of the adaxial staminodes were detected in one specieS. A peculiarity of the Disinae is that the entire apex of the median carpel develops into the rostellum, whereas its stigmatic portion emerges from the median carpel below the rostellum in later stages. The main diagnostic feature of the group is the reflexed position of the mature anther. However, it is shown here that this anther movement occurs in the later stages and that the initial anther is erect.     

Eria mêdogensis,a Probably Peloric Form of Eria Coronaria,with a Discussion on Peloria in Orchidaceae

Eria mêdogensis S. C. Chen et Tsi was recently found in southeastern Tibet, several specimens of which have been collected by various botanists since 1980. This is a “normal” entity with its habit very similar to that of Eria coronaria, from which it differs by having a regular perianth and longer bracts. We think it probable that this new entity is a peloric form of Eria coronaria. Peloria (or pelory) is a type of floral abnormality, which is found in many zygomorphicflowered taxa. It was first detected by Linnaeus (1744) in Linaria vulgaris, and then by others in Labiatae, Orchidaceae, etc. However, it is still an open question how to explain it theoretically and how to treat it taxonomically. In Orchidaceae, so far as our knowledge is concerned, peloria has been encountered in no less than 21 genera. In most cases, peloric flowers are found sporadically on an occassional plant, as seen in Cypripedium reginae and Eria oblitterata. Sometimes, however, peloric form may occur coexisting with normal-flowered form in one and the same species, as seen in Dendrobium tetrodon and Epipogium roseum. They are both abnormally peloric forms. It would not result in naming or renaming a plant taxonomically, whether the appearance of abnormally regular flowers on a normal-flowered inflorescence, or of abnormal-flowered individuals in normal-flowered species. In Phragmipedium lindenii, however, the case is different. It is quite “normal” and even of wider distribution than its nonpeloric allies P. wallisii and P. caudatum, from which it has once been considered to be derived. This is a normally peloric form. Whether it is a reversal or not, the appearance of a “normally” peloric taxon may be taken for a leap in the process of evolution. Taxonomically, we had better treat it as a separate species, especially when its origin is uncertain. For example, the entity just mentioned had been treated as a peloric va riety of Phragmipedium caudatum (var. lindenii) until 1975, when Dressler & Williams recognized it as an independent species based on the fact that its nonpeloric flowers occassionally found in a peloric population in Jungurahua of Ecuador are dissimilar in lip to those in P. caudatum. Garay (1979) considered it to be a peloric form of P. wallisii but maintained it at the specific level. This is indeed a good example of taxonomic treatment of normally peloric form. On the other hand, however, most of the regular-flowered entities in Orchidaceae are not peloric but rather primitive forms, such as Neuwiedia, Apostasia and Thelymitra, of which no less than 50 species have been reported since the eighteen century. They have never been regarded as peloric forms. Unfortunately, this has been neglected by some botanists. For instance, a hypothetically primitive orchid flower designed by Pijl & Dodson (1966) has a distinctly specialized lip with a short spur. In fact, in addition to the aforementioned genera we have some more examples of normally regular-flowered orchids. Among them Archineottia is the most interesting. This is a genus of four species, two of which are regular-flowered. Of special interest is that in this genus and its ally, Neottia, one can find all steps of column evolution from a simple form with stamen and style not fully united to a most complicated form in which they have well fused. Archineottia has a very primitive column, on which neither rostellum nor clinandrium is found but a terminal and undifferentiated stigma (Fig.2: 2, 4, 6, 8). In addition, there exists on the back of the column a thick ridge with its upper end joining the filament with which it is of same texture. It is obviously the lower part of the filament which has been adnate to the style (column). In Neottia, however, the column is much more advanced and very typical among the family. It has a very large rostellum and most complicated stigma structure (Fig. 10, 12, 14, 16, 18). One of the most interesting examples is Neottia acuminata, in which the stigma even becomes lamellate and almost backwards clasps the erect rostellum, but the perianth is more or less regular with its lip entire and somewhat similar to, but shorter and wider than, the petals. In these two genera there are altogether three species, namely Archineottia gaudissartii, A microglottis and Neottia acuminata, possessing regular or nearly regular perianth (Fig. 2: 1, 3, 17). They are obviously not peloric forms. We can not imagine, indeed, that a complicated form like Neottia acuminata or its allies would degenerate step by step into a simple form, and finally into a peloric form. Archineottia belongs to the subtribe Listerinae, which is closely related to Limodorinae, a rather primitivs subtribe with some genera possessing single pollen grain, relatively few and long chromosomes and monocotyledonous habit. Apparently, there is nothing surprising in the occurrence of some normally regular-flowered taxa, such as Archineottia, Diplandrorchis, Tangtsinia and Sinorchis, in these two primitive subtribes. Another instance is Aceratorchis, a genus formerly included in Orchis, from which it is distinguished by the entire lip which is more or less similar to the petals. Strictly speaking, however, its flowers are not truly regular. Two species have been described in this genus, but they were recently considered as conspecific. Aceratorchis tschiliensis is widely distributed from Hebei through Qinghai and Sichuan to northwestern Yunnan. It is cross-pollinated and produces seeds efficiently. All these indicate its normally primitive taxon, instead of peloria. It may be noted here that Asia is rich in members of Orchidioideae, as well as its primitive representatives. The occurrence of a normally regular-flowered form in Asia, whether representing primitive form of Orchis or Orchidioideae, is imaginable. In Orchidaceae, as mentioned above, regular flowers are not only found in some primitive taxa and peloric forms, but also in a few advanced groups. For example, a close investigation by the senior author (Chen 1979) on Satyrium ciliatum revealed that this species has hermaphrodite, staminate and pistallate forms, for which no less than nine names have been published. The flowers of its pistallate form are almost regular, in which nothing is found but three similar petals and an elongate style with three stigmatic lobes at its top (Fig. 2: 19). It is interesting to note that floral reversions in Orchidaceae are not always in connection with peloria. For example, Epidendrum triandrum of North America represents another kind of reversion. It is a reversal to abnormal polymery of stamens and not to abnormal regularity of perianth. Like Phragmipedium lindenii, it is also hereditary. We may give it a new name “Polyandrism” or something else, but, in fact, there is no essential distinction of this kind of reversion from peloria. It deserves mentioning that most of the regular-flowered entities, including primitive, advanced and peloric ones, occur in Asia and Australasia, where the Orchidaceae may have originated as pointed out by some botanists. We have good reason to verify the primitiveness and normality of many regular-flowered entities, but there exists no sufficient evidence for the impossible existances of normally regular-flowered species in those like Dendrobium, Eria, Lecanorchis, etc. For instance, Lecanorchis javanica, Dendrobium atavus and the new species described here are considered to be peloric forms, but it is only a conjecture, for no reason can be given for it. It is not impossible that some so-called peloric forms may prove to be truly primitive ones in the future. Of course, a closer investigation is needed. Summarizing the above, we may come to the following conclusions: 1. Regular or nearly regular perianth is a normal characteristic of orchids. It is chiefly found in some primitive taxa and sometimes also in certain peloric forms and advanced groups. Regular-flowered entities may not necessarily be peloric forms. 2. There exist two different types of peloria in Orchidaceae. One is abnormal form, with its peloric flowers appearing at random. The other is “normal” form, with its individuals all possessing peloric flowers. The latter is inheritable and can produce seeds efficiently, It would be best to treat it as an independent species taxonomically, especially when its origin is uncertain. 3. Although peloria has been considered to he a reversal as a whole, conditions vary from plant to plant. Some peloric forms have petal-like lip, and others have labellum-like petals. Sometimes the same plant produces different kinds of peloric flowers in different years, sometimes peloric flowers do not reappear upon the same plant. A few species can produce both peloric and normal individuals, but others produce peloric forms only. Peloria is in fact a term only used to cover the phase in which lip becomes similar to the petals. It is never all-embracing. We recognize the existance of peloria in Orchidaceae, but great care must be taken to distinguish truly peloric form from normally primitive one. It must be admitted that what causes peloria and even what is peloria are still problems awaiting solution. Acknowledgments: Our heartfelt thanks are due to Dr. Leslie A. Garay, Curator of the Orchid Herbarium of Oakes Ames, Botanical Museum of Harvard University, for his valuable suggestions during the preparation of this paper. We are also indebted to the artists, Mrs. Chunrung Liu and Mr. Chao-zhen Ji of our department, for their preparing the fine drawings.     

蜘蛛抱蛋亚族的花粉形态

本文研究并报道了百合科蜘蛛抱蛋亚族的花粉形态,主要结论如下：1．开口箭属含两种花粉类型即：(1)单槽、椭圆形;(2)无萌发孔、球形。具单槽、椭圆形花粉的种类含单型性核型,花形较小,柱头小而花柱短,雄蕊高于柱头;无萌发孔、球形花粉的种类则为单型性核型,花形较大,柱头常高度膨大,雄蕊常着生在花被筒基部。2．万年青属花粉为椭圆形,具单槽;蜘蛛抱蛋属花粉则为球形,无萌发孔;开口箭属花粉一部分与万年青属相似,另一部分则与蜘蛛抱蛋属雷同。3．蜘蛛抱蛋亚族中最原始的花粉类型为单槽椭圆形,具孔状或网状外壁纹饰。球形,无萌发孔,外壁具皱波状、瘤状或芽孢状纹饰的花粉为派生类型。4．蜘蛛抱蛋亚族种下花粉形状、萌发孔类型和外壁纹饰基本稳定,可作为分种特征。     

Pollen Morphology in the Subtribe Aspidistrinae (Liliaceae s. l.)

Pollen morphology in the subtribe Aspidistrinae is reported and the main viewpoints are summarized as follows: (1) Two major types of pollen grains, i.e., monosulcate,ellipsoidal pollen and inaperturate, spheroidal pollen, are identified in the genus Tupistra. The species with monosulcate, ellipsoidal pollen usually have monomodal karyotypes, brightcolored flower, smaller stigma, and stamens inserted at upper or middle part of perianth tube, while the inaperturate and spheroidal pollen is always found in the species with bimodal karyotypes, dingy-colored flower, swollen stigma and stamens inserted at the base of perianth tube. (2) Pollen grains in the genus Rhodea are monosulcate and ellipsoidal, while those in the genus Aspidistra are inaperturate and spheroidal, correspondingly similar to the second type of pollen grains in the genus Tupistra. (3) The most primitive pollen in the subtribe Aspidistinae is regarded as monosulcate and ellipsoidal, having perforate or reticulate exine sculpture. The inaperturate, spheroidal pollen with verrucate, gemmate or rugulate exine sculpture is considered derived; (4) Unlike those reported in other groups of the family Liliaceae, the infraspecific pollen shape, aperture type and exine sculpture in Aspidistrinae are basically stable and may serve as a taxonomic character.     

Changing partners in the dark: isotopic and molecular evidence of ectomycorrhizal liaisons between forest orchids and trees

In the mycorrhizal symbiosis, plants exchange photosynthates for mineral nutrients acquired by fungi from the soil. This mutualistic arrangement has been subverted by hundreds of mycorrhizal plant species that lack the ability to photosynthesize. The most numerous examples of this behaviour are found in the largest plant family, the Orchidaceae. Although these non-photosynthetic orchid species are known to be highly specialized exploiters of the ectomycorrhizal symbiosis, photosynthetic orchids are thought to use free-living saprophytic, or pathogenic, fungal lineages. However, we present evidence that putatively photosynthetic orchids from five species which grow in the understorey of forests: (i) form mycorrhizas with ectomycorrhizal fungi of forest trees; and (ii) have stable isotope signatures indicating distinctive pathways for nitrogen and carbon acquisition approaching those of non-photosynthetic orchids that associate with ectomycorrhizal fungi of forest trees. These findings represent a major shift in our understanding of both orchid ecology and evolution because they explain how orchids can thrive in low-irradiance niches and they show that a shift to exploiting ectomycorrhizal fungi precedes viable losses of photosynthetic ability in orchid lineages.     

Evolutionary trends in the androecium of theOrchidaceae

The evolution of the androecium in theOrchidaceae shows three major trends. There is a progressive trend in the degree of fusion of the filament(s) and staminode(s) to the gynoecium. Secondly, there is a reduction in the number of fertile anthers. Finally, there is a progressive change in the position of the base of the anther relative to the apex of the stigma; in the more primitive orchids the apex of the stigma is always higher than the base of the anther (this position is reversed in the higher orchids). All three trends reflect variation in the evolution of pollen dispersal and pollen reception mechanisms in theOrchidaceae. Trends in the evolution of the orchid anther(s) tend to parallel trends in the evolution of their pollinaria.     

Anthocyanins from flowers of the orchids Dracula chimaera and D. cordobae

The main anthocyanins from flowers of the orchids Dracula chimaera and D. cordobae were isolated from a purified methanolic extract by preparative HPLC. Their structures were determined to be cyanidin 3-O-(6"-O-malonyl-beta-glucopyranoside), cyanidin 3-O-(6"-O-alpha-rhamnopyranosyl-beta-glucopyranoside), cyanidin 3-O-beta-glucopyranoside, peonidin 3-O-(6"-O-alpha-rhamnopyranosyl-beta-glucopyranoside) and peonidin 3-O-(6"-O-malonyl-beta-glucopyranoside). The structure determinations were mainly based on extensive use of 2D and 1D NMR spectroscopy, UV-vis spectroscopy and MS. The anthocyanin contents of species belonging to the subtribe Pleurothallidinae including genus Dracula Luer (Orchidaceae) have previously not been determined. The high content of anthocyanin rutinosides found in D. chimaera and D. cordobae (78 and 28% of the total anthocyanin content, respectively) differs from previously analysed orchid species, in which glucose is found as the only anthocyanin sugar moiety.     

中国石斛属(兰科)植物新资料

在西藏开展兰科植物资源调查过程中,发现了2种石斛属(金石斛组)物种,通过文献和标本的查阅之后,分别确定为麦氏金石斛(Dendrobium macraei Lindl.)和西藏金石斛(D. ritaeanum King & Pantl.),两者均为中国首次记录。其中,麦氏金石斛与流苏金石斛(D. plicatile Lindley)近似,不同之处在于前者唇瓣中裂片边缘全缘,中裂片具2条纵脊,并仅延伸至唇瓣中部,先端凹; 西藏金石斛虽然植株与狭叶金石斛[D. angustifolium (Blume)Lindl.]近似,但该种花很小,萼片和花瓣不具紫色条纹且唇瓣长达1.4 cm,侧裂片三角形,花期时容易区分。同时,该文还提供了该2种石斛属植物详细的形态特征描述以及解剖图版等资料,凭证标本保存于西藏农牧学院标本馆。该发现丰富了中国兰科植物本底资料以及潜在药用植物资源储备,对中国兰科植物的生物多样性研究和药用兰科资源的调查具有重要意义。     

中国新分布种海伦兜兰的濒危状况

海伦兜兰Paphiopedilum helenae Aver.为中国新记录种。本种中萼片黄色,花瓣橙色,狭长圆形或略带匙形,边缘直,唇瓣橙褐色,退化雄蕊为近圆形。文章首次报道了海伦兜兰在中国新分布点的居群大小和繁育现状,并对其生境、伴生植物等作了详细描述。海伦兜兰所在的森林群落目前保护状况良好,但由于该地靠近村寨和公路,又不在保护区内,海伦兜兰居群仍然面临潜在的威胁。考虑到海伦兜兰在越南已遭受过度采集,建议进一步加强对该新分布兜兰属Pahiopdeilum植物的保护和监测。     

蓝堇草属(毛茛科)花形态发生的扫描电子显微镜观察

花的发生和发育过程研究可以发现早期进化的轨迹,为系统发育的研究提供重要线索。蓝堇草属(Leptopyrum)为毛茛科唐松草亚科一单种属,仅包含蓝堇草一种,其花的发生和发育过程仍为空白。为了深入理解唐松草亚科乃至毛茛科花发育多样性和演化规律,该文运用扫描电子显微镜(SEM)观察了蓝堇草各轮花器官的形态发生和发育过程。结果表明:该属植物所有的萼片、花瓣、雄蕊和雌蕊均为螺旋状发生,花器官排列式样也为螺旋状; 5枚萼片原基宽阔,5枚花瓣原基圆球形、位于萼片原基的间隔,且在后期表现为延迟发育现象,雄蕊原基较小、为圆球形; 花瓣原基和雄蕊原基连续发生,无明显的时空间隔,但与萼片原基有时空间隔; 心皮原基为马蹄形对折,柱头组织由单细胞乳突组成; 胚珠倒生、具单珠被。该属花器官螺旋状排列、胚珠具单珠被在唐松草亚科中是独有的性状,花发育形态学证据支持了该属的特殊性。     

东南亚兰科植物的物种多样性、生活习性及其传粉系统（附表）

兰科(Orchidaceae)植物广布于除两极和极端沙漠地区外的各种陆地生态系统,包括5个亚科800多属28 000多种。东南亚地区兰科植物种数约占世界的1/3,是兰科植物生物多样性热点区域之一。通过查阅文献及书籍等资料,该文系统整理了东南亚兰科植物物种种类及其扩散演化历史,并对其生活习性和传粉系统进行了归类。结果表明:(1)东南亚兰科植物8 855种,分属5亚科17族26亚族240属;(2)主要生活型为附生的有127属6 000种以上,地生97属2 000种以上,腐生13属约100种,藤本4属40余种;(3)根据整理出的东南亚79个属的兰科植物传粉系统发现,有44个属含有自动自交的物种,具报酬物的传粉系统有花粉(仅见于拟兰亚科)、芳香类物质(仅见于香荚兰亚科)和花蜜(5个亚科均有)等报酬物类型。欺骗性传粉系统广泛存在于各个亚科,包括食源性欺骗、性拟态、繁殖地拟态和信息素拟态等类型。东南亚兰科植物在物种、生活习性及传粉系统都展现出极高的多样性,对这些生物学特点的总结将为兰科植物的保育提供一定的理论基础和本底资料。     

广东山区兰科植物区系的研究

初步统计 ,广东山区共有兰科植物 71属 2 0 8种。其中以热带分布属 4 7属 ( 66.2 % )为主 ,占绝对优势 ,其次为热带—亚热带属 1 3属 ( 1 8.3% )。主要属为虾脊兰属、羊耳蒜属、玉凤花属、石斛属、兰属、石豆兰属 ,其中 2属为世界分布属 ,2属为热带分布属 ,2属为热带—亚热带分布属。广东山区兰科植物区系的地理成分较为复杂、多样 ,以热带亚洲成分 (占 39.4 % )为主导成分 ,其次为热带亚洲至热带大洋洲分布成分 ( 1 6.9% )。广东山区没有特有属 ,但特有种丰富 ,产中国特有种 39种 (占 1 8.8% ) ,其中广东特有种 6种 (占 2 .9% )。广东山区具有兰科植物从最原始到最进化各类型的代表。区系成份比较表明 ,本区与云南、广西和中南半岛兰科植物区系有较密切的联系。结果表明本区兰科植物区系的古老原始性 ;具有从热带向亚热带过渡的特点 ;与热带亚洲兰科植物区系具有密切的关系 ;可能是中国兰科植物演化中心的一部分。     

Developmental studies in orchid flowers I: Epidendroid and vandoid species

The floral development of 47 epidendroid and vandoid orchids was studied by means of scanning electron microscopy, paying special attention to the early development of the gynostemium (column) and its appendages. The following main conclusions are drawn: the lateral appendages of the adult gynostemium are homologous with the two lateral stamens of the inner whorl; their primordia are present even in species which lack prominent appendages in the adult gynostemium (incorporation of the sta-minodial primordia into the gynostemium during development). Ventral appendages observed in some species are supposed to be vestiges of the adaxial stamens on account of their early initiation. It is confirmed that the rostellum is the upper part of the median stigma lobe and that the lip corresponds to the inner median tepal. The affinities of the epidendroid and vandoid orchids are briefly discussed.     

A New Orchid Genus,Danxiaorchis, and Phylogenetic Analysis of the Tribe Calypsoeae

Background

Orchids have numerous species, and their speciation rates are presumed to be exceptionally high, suggesting that orchids are continuously and actively evolving. The wide diversity of orchids has attracted the interest of evolutionary biologists. In this study, a new orchid was discovered on Danxia Mountain in Guangdong, China. However, the phylogenetic clarification of this new orchid requires further molecular, morphological, and phytogeographic analyses.

Methodology/Principal Findings

A new orchid possesses a labellum with a large Y-shaped callus and two sacs at the base, and cylindrical, fleshy seeds, which make it distinct from all known orchid genera. Phylogenetic methods were applied to a matrix of morphological and molecular characters based on the fragments of the nuclear internal transcribed spacer, chloroplast matK, and rbcL genes of Orchidaceae (74 genera) and Calypsoeae (13 genera). The strict consensus Bayesian inference phylogram strongly supports the division of the Calypsoeae alliance (not including Dactylostalix and Ephippianthus) into seven clades with 11 genera. The sequence data of each species and the morphological characters of each genus were combined into a single dataset. The inferred Bayesian phylogram supports the division of the 13 genera of Calypsoeae into four clades with 13 subclades (genera). Based on the results of our phylogenetic analyses, Calypsoeae, under which the new orchid is classified, represents an independent lineage in the Epidendroideae subfamily.

Conclusions

Analyses of the combined datasets using Bayesian methods revealed strong evidence that Calypsoeae is a monophyletic tribe consisting of eight well-supported clades with 13 subclades (genera), which are all in agreement with the phytogeography of Calypsoeae. The Danxia orchid represents an independent lineage under the tribe Calypsoeae of the subfamily Epidendroideae. This lineage should be treated as a new genus, which we have named Danxiaorchis, that is parallel to Yoania. Both genera are placed under the subtribe Yoaniinae.     

北京松山国家级自然保护区兰科植物多样性及其保护评价

选取北京松山国家级自然保护区开展兰科植物多样性调查和分析,评估其保护现状。松山共有兰科植物12属18种,其中北方盔花兰为北京新记录种。在生活型方面,以地生兰为主,计14种（77．78％）,腐生兰4种（22．22％）;在分布区类型方面,属的区系成分以北温带分布为主（6属,5000％）,兼有旧世界温带分布（3属,25．00％）、世界分布（2属,16．67％）和旧世界热带分布（1属,8．33％）;种的区系成分以东亚分布为主（9种,50．00％）,兼有旧世界温带分布（5种,27．78％）和北温带分布（4种,22．22％）。松山兰科植物集中分布于北沟和小海坨山。通过综合分析松山兰科植物保护现状,提出生境评估、种群动态监测、建立迁地保护资源圃和加大宣传等都是切实加强兰科植物保护工作的可行措施。     

Two new species of the genus Pelexia (Orchidaceae, Spiranthinae) from South America

Szlachetko, D. L. 1995. Two new species of the genus Pelexia (Orchidaceae, Spiranthinae) from South America. - Nord. J. Bot. 15: 173–175. Copenhagen. ISSN 0107–055X.
Pelexia sheviakii and Pelexia collocaliae are described as new species from Ecuador and Paraguay respectively. Pelexia sheviakii differs from Pelexia bonariensis and any other species related by its lip form, which is rhomboid, has no constriction, and with basal lip thickenings produced on upper surface of claw. The most characteristic features of Pelexia collocaliae are U-shaped callus at apices of petals, erect flowers, straight lateral sepals and narrow lip with two small calli near isthmus.     

Seedlings of Neuwiedia (Orchidaceae subfamily Apostasioideae) have typical orchidaceous mycotrophic protocorms

Naturally occurring seedlings of Neuwiedia veratrifolia were found in three localities in Sabah, Borneo, Malaysia. Seedlings consisted of an irregular oblong protocorm and a terminal leafy rooted shoot. Protocorms contained mycotrophic tissue of the kind typical of orchid mycorrhiza (tolypophagy). This finding demonstrates an important synapomorphy between Neuwiedia and other orchids and strongly supports the monophyly of Orchidaceae in the broad sense, including apostasiod orchids.     

Speciation in the Orchidaceae: confronting the challenges

The Orchidaceae is renowned for its large number of species (19,500) and its many diverse, even bizarre, specialized pollination systems. One unusual feature of orchids is the high frequency of food deception whereby animal pollination is achieved without providing nectar, pollen or other food rewards. Food-deceptive pollination is estimated to occur in approximately one-third of all orchids. Equally intriguing is pollination by sexual deception whereby pollination is achieved by the sexual attraction of male insects to the orchid flower. Sexual deception is found in several hundred species representing multiple lineages. Given their rich species diversity and extraordinary plant-animal interactions, orchids clearly offer exciting research opportunities in pollination biology, reproductive isolation and speciation, yet surprisingly they remain under-represented in scientific investigations both in these fields and more generally. In this special issue of Molecular Ecology, Moccia et al. provide an exemplar study that combine multiple lines of evidence to illuminate the mechanism of reproductive isolation between two closely related food-deceptive orchids. Their study demonstrates that many of the challenges that confront orchid researchers and impede progress in our understanding of speciation in the Orchidaceae can be overcome by the creative application and integration of both old and new tools in ecology and genetics.     

高黎贡山兰花的多样性

对高黎贡山兰科植物的生物地理学和多样性进行了研究。1.兰科是高黎贡山种子植物中最大的科,包括75属265种。2.高黎贡山兰花起源于新、旧世界的热带和温带, 热带属占60%(45属),温带属占38.67%(29属),包括2个云南特有属。但是,高黎贡山兰科植物与地中海地区和中亚地区的联系十分微弱。3.高黎贡山的兰花以地生兰为主。这里,57.33%(43属)为地生兰,而附生兰和腐生兰仅分别为31属和3属。4.兰花物种的分布区式样表明高黎贡山兰花以温带兰为主 温带兰占总种数的69.43%(184种),包括东亚成分即滇西高黎贡山-东喜马拉雅分布的种和中国西南部特有种,它们是高黎贡山兰花区系的核心。5.高黎贡山兰科的特有现象在于1)具有云南二个特有属蜂腰兰Bulleyia和反唇兰Smithorchis;2)有高黎贡山特有种21个,如泸水兜兰Paphiopedilum markianum,贡山风兰Cymbidium gongshanense,贡山贝母兰Coelogyne gongshanense,热带附生兰——万带兰亚科在高黎贡山没有形成特有种;3)高黎贡山北段的特有种比南段丰富贡山有14种,腾冲仅有4种; 海拔1800～2100 m的梯度带特有种最多(13种);4)高黎贡山有云南特有种10种,其中小花槽舌兰Holcoglossum junceum是一个热带种,因为板块位移而来到了亚热带地域;5)高黎贡山的兰科植物中有19.25%(51种)是中国特有种,它们出现在高黎贡山,分布在云南其他地区和西南的一些省区。高黎贡山特有种,分布到高黎贡山的云南特有种和分布到高黎贡山的中国特有种一共为82种,占高黎贡山兰科总种数的30.91%, 兰科在高黎贡山是一个特有化程度很高的类群。