虎耳草属山羊臭组的界定和系统发育: 核糖体DNA ITS序列证据

虎耳草属Saxifraga山羊臭组sect. Ciliatae是该属中最大的一个组, 共有175种, 主要分布在喜马拉雅地区, 我国分布有166种, 占总种数的95%; 其中, 112种为中国特有。约80%的种类分布在我国青藏高原和西南地区, 是中国喜马拉雅植物成分的代表类群。山羊臭组内物种分化十分显著, 分类处理也很困难, 该组是否为单系类群, 组下的系统发育关系也不清楚, 均需进一步验证。本文测定了虎耳草属山羊臭组及其他组33种植物样品的核糖体DNA内转录间隔区ITS序列, 并从GenBank调取虎耳草组sect. Saxifraga等组和近缘属唢呐草属Mitella共22种植物的该序列。ITS分析结果表明: (1)所研究的山羊臭组类群聚为单独一支, 而且与垫状组sect. Porphyrion、虎耳草组、球茎组sect. Mesogyne和仅在欧洲分布的sect. Cymbalaria和sect. Cotylea等8个组聚成的另一分支构成姊妹群; (2)根据形态特征建立的山羊臭组的3个亚组即唐古拉亚组subsect. Hirculoideae、莲座状亚组subsect. Rosulares和具芽亚组subsect. Gemmiparae各自聚为一支, 但是莲座状亚组这一支的支持率较低。同时, 山羊臭组的鞭匐枝亚组subsect. Flagellares和subsect. Hemisphaericae的代表类群单独聚为一支, 位于具芽亚组类群分支内部而不能成立; (3)唐古拉亚组和莲座状亚组又聚为一亚分支与具芽亚组构成姊妹群, 而且具芽亚组最早从山羊臭组这一支中分化出来。我们的研究还发现山羊臭组内种间形态分化较大, 而ITS碱基变异较小, 这可能是山羊臭组类群在青藏高原及毗邻地区的高山环境下物种快速分化的结果。     

中国锦鸡儿属的分子系统发育

测定了中国锦鸡儿属Caragana各属下分类群20个代表种的ITS、trnL-F和trnS-G序列.基于3种DNA片段的单独分析所获得的系统发育树具有相似的拓扑结构;3种片段的合并分析提高了各分支的支持度,并获得了相似的系统发育树.落轴亚属subgen.Caragana的种类构成了一个在系统树上首先分化出来的单系分支,与形态特征和地理分布的研究一致.短齿系ser. Occidentales和长齿系ser. Bracteolatae的代表种构成了1个单独的分支,因此短齿系应被放入长齿系所属刺叶组sect.Longspina 而不是针刺组sect.Spinosae或sect.Pruinosa.分子系统学证据支持依据叶片宽窄在掌叶组sect.Frutescentes中再划分2个系的形态学研究结论;但Ser.Dasyphyllae和针刺系ser.Spinosae的亲缘关系较近,系统发育分析的结果似乎不支持在针刺组中单独划分2个系.宿轴类的物种聚成一个单系的分支,因此应被处理为一个组--鬼箭组sect.Jubatae;荚果里面被毛和无毛的种类各自构成2个小支,支持依据该特征在组下分系.系统树显示Sanczir定义的sect.Tragacanthoides然为多系类群,应将该组中所包含的刺叶组、针刺组、和鬼箭组的种类划分出来.基于ITS的遗传距离表明卷叶锦鸡儿C. ordosica与藏锦鸡儿C, tibetica应该是2个不同的种.     

对翼蓼(蓼科)属级位置的重新探讨

通过对翼蓼Pteroxygonum giraldii Damm. &; Diels及相关属(蓼属Polygonum、何首乌属Fallopia、虎杖属Reynoutria、荞麦属Fagopyrum和金线草属Antenoron)的形态观察、果实解剖学观察、花被片脉序观察、花粉形态、核型分析, 以及ITS序列的分析确定了翼蓼和荞麦F. esculentum Moench较远的亲缘关系。其中我们发现翼蓼果实基部有三个角状物明显不同于其他属果实的形态特征。翼蓼外果皮明显加厚, 并有零星散布的波状内腔, 而荞麦的外果皮很薄, 细胞不等径, 中果皮极厚。以上证据证明了翼蓼与荞麦属亲缘关系较远。在观察荞麦属和翼蓼的花被片脉络时发现了两种不同的脉序类型, 符合将荞麦属分为两个组的划分。翼蓼花被片脉序为三出状, 支持将翼蓼归为Persicarieae族。对翼蓼及荞麦属植物的花粉进行比较后, 发现荞麦属植物的花粉网孔有明显的内凹穿孔而翼蓼却没有, 结果表明二者亲缘关系较远。通过对nrDNA ITS区域序列分析得出翼蓼及相关属为一个单系类群, 含有两个稳定的分支: 第一个分支由蓼属(萹蓄组sect. Avicularia)、何首乌属、虎杖属的植物组成, 第二个分支由蓼属(刺蓼组sect. Echinocaulon、蓼组sect. Polygonum、分叉蓼组sect. Aconogonon、拳参组sect. Bistorta、翼蓼和荞麦属植物组成。同时第二个分支又分成了两个亚分支, 蓼属(刺蓼组、蓼组、分叉蓼组、拳参组)和翼蓼属Pteroxygonum植物属于第一个亚支而荞麦属植物属于第二个亚支。结果支持翼蓼不属于荞麦属的范畴。实验结果显示翼蓼是个单型属, 属于Persicarieae族。     

珍珠菜属系统发育关系的初步研究

本文运用形态学性状对珍珠菜属（Lysimachia)进行系统发育分析。内类群包括珍珠菜属29个代表种以及珍珠菜族其它单种、寡种属;仙客来属（Cylclamen)被选作外类群。最简约性分析表明,珍珠菜属并不构成－自然分类群;在其严格一致化树的二岐分支中,异花珍珠菜（L.crispidens)单独构成一支,其它所有内类群构成一支。香草亚属（subgen.Idiophyton)、木黄连花亚属（subgne.Lysimachiopsis)以及珍珠菜亚属（subgen.palladia)均表现为单系群,而黄连花亚属（subgen.Lysimachia)则为一异形的并系群。球尾花亚属（subgen.Naumburgia)仍“内藏”于珍珠菜属的主体之中。而喉鳞花亚属（subgen.Seleucia)则偏离出来而与七瓣莲属（Trien talis)构成姐妹群。如何准确地界定珍珠菜属和进行属下分类群的划分,还需进一步研究。     

新疆石竹属野生种核糖体DNA的ITS序列与亲缘关系

新疆是我国石竹属植物分布和分化中心,种质资源丰富。通过采用PCR直接测序法,对新疆石竹属（Dianthus)植物野生种共8个种及外类群（Lychnis coronata Thunb)rDNA的ITS区（包括ITS－1,5.8S,rDNA和ITS－2）进行序列测定。研究结果说明,新疆石生属植物的ITS序列总长度为617－621bp,长度变异较小,仅相差4bp,种间序列同源性很高,达97．6％－99．8％,外类群的序列同源性为80％左右。ITS区序列在石竹属内是相当保守的,石竹属物种间序列变异位点基本上是转移多于颠换,且转移率较高,转换／颠换率为1．0－3．0。系统地位和亲缘关系分析表明分布于中国的石竹属植物3个组即齿瓣组（sect.Barbulatum Williams)和石竹组（sect.Dianthus),遂瓣组（sect.Fimbriatum Williams)的亲缘关系较远,而sect.Dianthus与sect.Fimbriatum Williams的亲缘关系较近。ITS系统发育树揭示了石竹组起源早于遂瓣组和齿瓣组,其结果与传统形态学论述存在很大差异。     

菝葜科基于形态学证据的系统发育分析

对全世界范围分布的菝葜科Smilacaceae的79个代表种(包括了全部的属和组), 以分布于南美洲的Philesia Comm. ex Juss.和Lapageria Ruiz &; Pav.属为外类群, 选取包括花粉和染色体性状在内的47个广义的形态学性状进行了分支分类系统发育分析, 同时以表征分类的方法构建了距离树(NJ)辅助分析, 首次对世界分布的菝葜科各属间及属内的系统发育关系作了探讨。(1)Ripogonum与菝葜属Smilax +肖菝葜属Heterosmilax互为姐妹群, 但是距离较远, 支持将类菝葜属(新拟中文名)Ripogonum独立为科的观点; (2)肖菝葜属在菝葜科内处于较为进化的分支上, 并与菝葜属土茯苓组sect. Coilanthus的部分种组成一个具较高支持率(88%)的单系分支, 分析表明肖菝葜属并非是一个好属, 应归入菝葜属; (3)菝葜属6个组的划分大都没有得到支持, 只有东亚北美间断分布的草本菝葜组sect. Nemexia的单系得到很好的支持(93%); (4)分布于南美洲巴西的种类聚为一个单系类群, 表明它们可能有共同的起源, 但由于取样局限, 南美洲种类的系统地位有待进一步研究。     

广义飞蛾藤属(旋花科)的分支系统学分析

基于33个广义的形态学性状,对广义飞蛾藤属Porana s．l．进行了分支系统学分析。经过简约性分析,得到了10个同等简约的分支树。10个同等简约树的严格一致化树表明,广义飞蛾藤属是一较为自然的分类群。与广义飞蛾藤属的孢粉学、种皮微形态学研究结果一致,分支分析的结果不支持将广义飞蛾藤属拆分为4个或5个独立的属,应在属内划分分类等级。在整个形态分支树中广义飞蛾藤属4个亚属呈并列2个分支,其中飞蛾藤亚属(subg．Porana)和白花叶亚属(subg．Poranopsis)形成姐妹群构成一分支,三翅藤亚属(subg．Tridynamia)和棒状亚属(subg．Dinetus)以姐妹群的关系构成另一支。鉴于分支分析的Bootstrap支持率不高,广义飞蛾藤属范畴的最后界定和属内等级的划分仍有待于进一步研究。     

中国紫金牛属的分支分类学研究

基于60个形态学性状,对中国广义报春花科（Primulaceae s.l.）紫金牛属（Ardisia）90个分类群的系统发育关系运用分支分析方法进行了分析。采用最简约性分析得到了100个同等简约树。50%多数规则一致树的分支结构与以前建立的紫金牛亚属划分系统基本一致。外类群酸藤子属、铁仔属、密花树属聚在分支树的最基部,紫金牛属为一单系类群。形态分支树的一致性指数和保持性指数和各分支内部支持率均较低,只在种与变种或亚种之间获得较高的支持率。高木亚属、腋序亚属、短序亚属、顶序亚属处于分支树较为基部的位置,推测这四个亚属的类群在紫金牛属中较为原始;圆齿亚属和锯齿亚属共同组成一大支,二者亲缘关系紧密,推测这两个亚属为该属中最为进化的类群。结合形态学对属内系统发育关系进行了讨论和推测了一些性状的演化趋势,以期为分类修订提供依据。     

栝楼属基于核糖体ITS序列的系统发育分析

栝楼属（Trichosanthes）是葫芦科(Cucurbitaceae)中一个种类较多、药用价值较大的属。本文基于ITS序列分析了栝楼属16个种的系统发育关系。聚类分析表明：在组的划分上,具有分类争议的截叶组(sect. Truncata)与大苞组(sect. Involucraria)形成一大支,处于一亚分枝位置,不支持独立成组。在属内分类地位上,在核酸水平不支持贵州栝楼(T.guizhouensis)为一独立种,结合形态特征建议并入双边栝楼(T.rosthornii)。大方油栝楼(T.dafangensis)与小苞组(sect. Trichosanthes)成为姊妹群,处于一个向叶苞组(sect. Foliobracteola)过渡位置,结合其形态特征,建议作为小苞组(sect. Trichosanthes)成员。     

壳斗科栎属青冈亚属的花粉形态及其系统学意义

对栎属青冈亚属17个种及炭栎花粉形态进行扫描电镜观察。结果表明:青冈亚属和炭栎花粉均为三拟孔沟,球形至长球形,(15～28.0)μm×(15.0～25.6)μm。花粉外壁纹饰可划分为3种:(1)蠕虫状(包括皱波状)、(2)聚合颗粒状、(3)棒状或小刺状。各纹饰在组间镶嵌分布。棒状及小刺状纹饰为栎属花粉较为原始式样,并为青冈亚属与高山栎组及部分巴东组(sect.Cerris)共有,推测其间具有较其它栎类更为接近的亲缘关系,可能为广义栎属中较为基础的类群,而与栎亚属sect.Quercuss.s.,Lobatae和Protobalanus关系较远。花粉形态对广义栎属系统分类价值仅适用于较高分类阶元。     

Crossability analysis in subgenus Tulipa of the genus Tulipa L.

A range of almost 1400 cross combinations has been carried out between 31 species of Tulipa subgenus Tulipa. Most of the sections are well separated reproductively from each other. The designated species aggregates in section Clusianae appeared to be intersterile. Also in section Kolpakowskianae the species, as far as used, cannot be combined. Some crosses between species of section Tulipanum succeeded. The species of sections Eichleres and Tulipa (including the cultivated tulip T gesneriana ) could be combined in various ways, although the highest level of seed set was achieved within either section. The crossability data support the current taxonomic division. The level of reproductive isolation between sympatric species is discussed, and the importance of crossability studies for plant breeding in Tulipa pointed out briefly.     

Molecular phylogenetics of the giant genus Croton and tribe Crotoneae (Euphorbiaceae sensu stricto) using ITS and TRNL-TRNF DNA sequence data

Parsimony, likelihood, and Bayesian analyses of nuclear ITS and plastid trnL-F DNA sequence data are presented for the giant genus Croton (Euphorbiaceae s.s.) and related taxa. Sampling comprises 88 taxa, including 78 of the estimated 1223 species and 29 of the 40 sections previously recognized of Croton. It also includes the satellite genus Moacroton and genera formerly placed in tribe Crotoneae. Croton and all sampled segregate genera form a monophyletic group sister to Brasiliocroton, with the exception of Croton sect. Astraea, which is reinstated to the genus Astraea. A small clade including Moacroton, Croton alabamensis, and C. olivaceus is sister to all other Croton species sampled. The remaining Croton species fall into three major clades. One of these is entirely New World, corresponding to sections Cyclostigma, Cascarilla, and Velamea sensu Webster. The second is entirely Old World and is sister to a third, also entirely New World clade, which is composed of at least 13 of Webster's sections of Croton. This study establishes a phylogenetic framework for future studies in the hyper-diverse genus Croton, indicates a New World origin for the genus, and will soon be used to evaluate wood anatomical, cytological, and morphological data in the Crotoneae tribe.     

Revisiting of Carex sect. Confertiflorae s.l. (Cyperaceae): New data from molecular and morphological evidence and first insights on Carex biogeography in East Asia

Carex sect. Confertiflorae s.l. is a medium-sized species group (ca. 40 species) with its center of diversity in E Asia (China and Japan). According to morphological traits, the section has been proposed to split into two sections (sects. Confertiflorae sensu Ohwi and Molliculae Ohwi) up to five different ones (sects. Confertiflorae s.s., Molliculae, Dispalatae Ohwi, Ischnostachyae Ohwi, and Alliiformes Akiyama). Recent phylogenetic reconstructions showed Confertiflorae s.l. not to be monophyletic, as species traditionally considered part of it were found to belong to other clades, whereas species traditionally ascribed to other sections were nested within it. In this study, we investigated the phylogenetic structure, morphological affinities, and biogeographic history of sect. Confertiflorae s.l. We employed a taxon-based approach to explore the morphological affinities of the species considered in sect. Confertiflorae and compared the micromorphology of the nutlets of almost all the taxa using SEM. We included 40 samples representing 31 species/subspecies of sect. Confertiflorae s.l. and used two nuclear (ETS and ITS) and three plastid (trnL-F, matK, and rpl32-trnL ^UAG) molecular markers to reconstruct the phylogeny of the group. The phylogenetic analyses confirmed the polyphyly of sect. Confertiflorae s.l., whose representatives were found within five distinct clades. From these, two clades, sect. Confertiflorae and sect. Molliculae, were found to be closely related and contained the majority of the species. The composition of the two clades agreed with the morphological structure of the group, and we confirmed an exclusive combination of features (namely color of basal sheaths, presence of bract sheath, peduncle of lowest spike, inflorescence sex distribution, shape of pistillate glume apex, and color and veins of utricle, among others) characterizing each of the two clades. The origin of the two clades was found to be in the early Pliocene; however, the majority of the diversification events within each clade took place during the Pleistocene. This illustrates that although Asia has been regarded as having little potential ecological space for Carex to diversify due to its climate stability, groups of sedges sub-endemic from that area may have a fairly recent origin related to glaciations. We proposed the rearrangement of sect. Confertiflorae as previously conceived as three independent sections: the monotypic Alliiformes, sect. Molliculae, and sect. Paludosae.     

Reappraisal of the generic status of Pteroxygonum (Polygonaceae) on the basis of morphology,anatomy and nrDNA ITS sequence analysi

Gross morphology, fruit anatomy, tepal venation, pollen morphology, chromosome number and ITS sequence of Pteroxygonum Damm. & Diels as well as other related genera (Polygonum, Fallopia, Reynoutria, Fagopyrum, and Antenoron) have been investigated to evaluate the generic status of Pteroxygonum. Pt. giraldii Damm. & Diels has three sharp horns at the base of fruit, which is distinctive among all the genera investigated. Upon observation of fruits under a light microscope (LM), the exocarp of Pt. giraldii is usually thickened and delimited by the rectangular cells with some sporadic undulating lumen, while that of Fagopyrum is thin-walled and isodiametric to rectangular in the cell shape. Analysis of tepal venation was performed under a stereomicroscope, and two types of tepal venation were found in Fagopyrum and Pteroxygonum. The type I is trifid, observed in Pt. giraldii, F. esculentum Moench, F. dibotrys (D. Don) Hara and F. tataricum (L.) Gaertn. The type II, found in F. caudatum (Sam.) A. J. Li, F. urophyllum (Bur. & Franch.) H. Gross and F. gracilipes (Hemsl.) Damm. ex Diels, has the main vein extending from tepal base with some secondary veins. Evidence from tepal venation supports the previous classification in which Fagopyrum can be divided into a large-achene group and a small-achene group. Pollen morphology was investigated under a scanning electron microscope (SEM). The exine ornamentation of Pt. giraldii was finely reticulate with lumina diameter wider than muri width. The exine ornamentation in all the examined Fagopyrum species is, however, prominently sunken punctuate. The phylogenetic analysis of nuclear ribosomal DNA (nrDNA) ITS sequences in Pteroxygonum and related genera indicated that all the species form a well-supported monophyletic group with two clades. One includes Polygonum sect. Avicularia Meisn., genus Fallopia and genus Reynoutria, and the other consists of other sections of Polygonum, genus Fagopyrum and Pteroxygonum. The latter clade can be divided into two subclades. Fagopyrum species compose the first one, while Pteroxygonum giraldii, species of Polygonum (except sect. Avicularia) and Antenoron form the second one. In consideration of the above evidence, we conclude that Pteroxygonum is an independent genus in tribe Persicarieae, and should not be merged into the genus Fagopyrum.     

Molecular phylogenetics reveals Leontodon (Asteraceae, Lactuceae) to be diphyletic

The plastid matK gene, trnL/F spacer, and nuclear rDNA ITS were sequenced for 36 species of Leontodon and 29 taxa of related genera of tribe Lactuceae. Phylogenetic relationships inferred from the independent and combined data are largely congruent and reveal that Leontodon sensu lato (s.l.) as presently defined is diphyletic: L. subgenus Leontodon forms a clade with Helminthotheca, Picris and Hypochaeris as sister genera, whereas L. subgenus Oporinia appears as a separate clade with strong bootstrap support and is thus better treated as a separate genus. Previous sectional classifications of Leontodon s.l. are considered in the light of DNA and additional morphological and karyological data. Support is presented for a core group of Hypochaeridinae sensu stricto (s.s.) with the two clades of Leontodon s.l., Helminthotheca, Picris, and Hypochaeris, whereas Urospermum, Hyoseris, Aposeris, and Rhagadiolus appear to be positioned more distantly.     

Phylogenetic relationships of African killifishes in the genera Aphyosemion and Fundulopanchax inferred from mitochondrial DNA sequences

We have analyzed the phylogenetic relationships of 52 species representing all defined species groups (J. J. Scheel, 1990, Atlas of Killifishes of the Old World, 448 pp.) of the African aplocheiloid fish genera Aphyosemion and Fundulopanchax in order to examine their interrelationships and to reveal trends of karyotypic evolution. The data set comprised 785 total nucleotides from the mitochondrial 12S rRNA and cytochrome b genes. The molecular-based topologies analyzed by both maximum parsimony and neighbor-joining support the monophyly of most previously defined species groups within these two killifish genera. The genus Aphyosemion is monophyletic except for the nested position of Fundulopanchax kunzi (batesi group; subgenus Raddaella) within this clade, suggesting that this taxon was improperly assigned to Fundulopanchax. The remaining Fundulopanchax species sampled were supported as being monophyletic in most analyses. Relationships among the species groups in both genera were not as strongly supported, suggesting that further data will be required to resolve these relationships. Additional sampling from the 16S rRNA gene allowed further resolution of relationships within Fundulopanchax, more specifically identifying the nonannual scheeli group as the basal lineage of this otherwise annual genus. Chromosomal evolution within Aphyosemion has been episodic, with the evolution of a reduced n = 9-10 metacentric complement having occurred in multiple, independent lineages. Polarity of chromosomal reductions within the elegans species group appears to support previous hypotheses concerning mechanisms of karyotypic change within the genus Aphyosemion.     

Molecular phylogeny of Chinese Rubia (Rubiaceae: Rubieae) inferred from nuclear and plastid DNA sequences

Rubia L. is the type genus of the coffee family Rubiaceae and the third largest genus in the tribe Rubieae, comprising ca. 80 species restricted to the Old World. China is an important diversity center for Rubia, where approximately half of its species occur. However, its internal phylogenetic relationships are still poorly understood. The objective of the present study is to contribute to the phylogenetic relationships within Rubia, using the nuclear internal transcribed spacer and six plastid markers and focusing on species from China. Twenty-seven species of Rubia were sampled to infer their phylogeny using Maximum parsimony, Maximum likelihood, and Bayesian analyses. The monophyly of Rubia is supported, provided that R. rezniczenkoana Litv. is excluded from Rubia and transferred to Galium as a new combination: G. rezniczenkoanum (Litv.) L. E Yang & Z. L. Nie. Within Rubia, two clades are clearly supported. They correspond to the traditional sect. Rubias.l. (A) and sect. Oligoneura Pojark. (B), and are morphologically mainly separable by their pinnate (A) versus palmate (B) leaf venation. Plesiomorphic features are the pinnate leaf veining in sect. Rubia s.l. and the occurrence of some species with opposite leaves and true stipules in sect. Oligoneura. In sect. Oligoneura one can assume an evolution from species with opposite leaves and true stipules (as in the R. siamensis Craib group) to those with whorls of two leaves and two leaf-like stipules (as in ser. Chinenses and the R. mandersii Collett & Hemsl. group) and finally with whorls of 6 or even more elements (as in ser. Cordifoliae). The correlation between clades recognized by DNA analyses and available differential morphological features is partly only loose, particularly in the group of R. cordifolia with 2×, 4×, and 6× cytotypes. This may be due to rapid evolutionary divergence and/or hybridization and allopolyploidy.     

Phylogeny and taxonomy of Afrocayratia,a new genus of Vitaceae from continental Africa and Madagascar

The genus Cayratia Juss. in the traditional sense (i.e., Cayratia s.l.) of the grape family has been shown to be non‐monophyletic. Previous studies supported the splitting of Cayratia s.l. into three genera, that is, Cayratia s.s., Causonis Raf., and a new genus representing the African Cayratia clade. However, the morphology of the African Cayratia clade has not been studied carefully and its phylogenetic position within Vitaceae remains unclear. Our study integrates molecular, distributional, and morphological data and supports the recognition of the new genus Afrocayratia from continental Africa and Madagascar. Phylogenetic analyses strongly support the monophyly of Afrocayratia and resolve it as a sister of Cayratia s.s. based on the chloroplast data, but it is placed sister to Cyphostemma based on the internal transcribed spacer dataset. Molecular dating suggests that Afrocayratia split with Cayratia s.s. during the Paleocene, but that the extant species of Afrocayratia did not diversify until the early Miocene. Afrocayratia differs from its allied genera in having short stigmas and seeds with subcircular ventral infold cavities in cross‐section. Three clades are detected within Afrocayratia, with A. debilis (Baker) J.Wen & L.M.Lu as the first diverged lineage. The second diverged lineage includes A. delicatula (Willems) J.Wen & Z.D.Chen and A. gracilis (Guill. & Perr.) J.Wen & Z.D.Chen. The third diverged lineage includes A. imerinensis (Baker) J.Wen & L.M.Lu, A. longiflora (Desc.) J.Wen & Rabarijaona, and A. triternata (Baker) J.Wen & Rabarijaona from Madagascar, which form a monophyletic group that diverged from the second lineage in the middle Miocene. Combining the morphological and molecular evidence, we formally describe the new genus Afrocayratia, make seven new combinations, and provide a key to species of the genus.