铁线莲属一新分类系统

A new system of classification of the genus Clematis (Ranunculaceae)

提出毛茛科Ranunculaceae铁线莲属Clematis一新分类系统。首先,简要回顾了此属的分类学研究历史,继对此属的营养器官和生殖器官的重要形态特征和花粉特征进行了分析,揭示出一系列演化趋势。这些趋势,尤其是萼片和雄蕊的演化趋势说明在现存的铁线莲属植物中,绣球藤Clematismontana与其少数近缘种的花构造最接近比铁线莲属原始的银莲花属Anemone,因此,包括绣球藤等植物的绣球藤组sect.Cheirpsis被认为是铁线莲属的原始群。主要根据花构造对铁线莲属现存的15组的亲缘关系进行了分析,发现它们是在4条演化干(绣球藤干、欧洲铁线莲干、尾叶铁线莲干、长瓣铁线莲干)的演化过程中先后形成的。本文将此4条演化干处理为亚属。最后做出属下各级分类群的系统排列,并给出简要的形态特征。

A new system of classification of the genus Clematis is proposed. The taxonomic history of the genus is briefly reviewed. On the basis of the analyses of various morphological and palynological characters, evolutionary trends of some characters are revealed as follows：1. Habit： perennial herb（subshrub, woody vine）shrub.2. Seed germination： epigeal→hypogeal.3. Leaf： （a）phyllotaxy： alternat→opposite→verticillate.（b） division： simple, palmatifid[palmatisect→ternate（biternate ,1-3-pinnate→3-4-pinnatisect.）simple, undivided→temate.]（c） texture： herbaceous→papery→subcoriaceous or coriaceous.4. Inflorescence： （a） position： terminal→terminal and axillary→axillary. （b） type： pedunculate, bibracteate, several-flowered cyme. （i） 3-4 times branched, 20-35-flowered cyme→many-branched ca. 100-flowered panicle. （ii） 1-flowered cyme→a single flower, pedicellate, but with peduncle and bracts wanting.5. Flower： （a） Sexuality： bisexual→unisexual. （b） Posture： erect, with straight pedicel→pendulous, with recurved pedicel.6. Sepal： （a） number per flower： 4 or 5→6-8. （b） aestivation： valvate→imbricate. （c） colour： white or yellow-blue, purple or red.（d） spreading direction： spreading→ascending→erect. （e） texture： herbaceous or papery→subcoriaceous or coriaceous. （f） shape： obovate→obovate-oblong, oblanceolate, lanceolate or oblong→narrowly oblong→linear.（g） apex： rounded or obtuse→acute→ acuminate→attenuate （h） margin indumentum： glabrous or puberulous→with a narrow velutinous strip （i） margin dilation： not dilated→dilated. （j） indumentum of adaxial surface： glabrous→puberulous→velutinous.7. Stamen： （a） indumentum： glabrous→filament hairy yet anther glabrous→both filament and anther hairy.（b） filament： （i） linear→roximally or distally widened, or entirely so. （ii） flat→rugose.（c） anther： oblong, 0.8-3.5 mm long→narrowly oblong, 2-6 mm long→linear, up to 7-10 mm long.（d） connective： not projected→apex minutely apiculate, with an apiculum ca. 0.1 mm long→apex with a conic or subglobose projection O. 1-0.2 mm long→apex with a subulate projection up to 4 mm long or with a narrowly lamellate projection 1-10 mm long.8. Pollen： 3-colpate（pantocolpate → pantoporate,pantoporate）9. Staminode： （a） absent in bisexual flower→present in bisexual flower. （b） number per pistillate flower： numerous→few→zero.10. Style： not elongate→elongate and plumose→slightly elongate and appressed-puberulous, then tail-like or subulate in shape→very short, slightly or not elongate, appressedpuberulous or glabrous. 11. Fruit： not complanate, nor rimmed, nor marginate→complanate, narrowly to tumidly rimmed→complanate, broadly marginate or winged. According to the evolutionary trends mentioned above and mainly according to the floral structure, the relationships among the 15 sections of Clematis are discussed, and four evolutionary stocks are recognized. Of them, the C. montana stock, in which C. brevipes, C. potaninii, C. montana etc., all with spreading, white, obovate sepals and glabrous stamens, are included, is regarded as the primitive group of the genus, whereas the other three, C. vitalba stock, C. connata stock, and C. alpina stock, are regarded as more advanced. All these four stocks might be derived from a putative extinct primitive group of the genus, which might possess the most primitive vegetative and reproductive characters. The four stocks are all treated as subgenera in the present system. Finally, a systematic enumeration of all the infrageneric taxa is presented and their brief diagnoses are given.