Taxonomic Study On Typha Sect.Bracteolatae (Typhaceae) In China

Typha L (Typhaceae), one of the most common aquatic plants found in marshes and shallow water, is almost cosmopolitan. There are about20species around the world, approximately10-12of them are found in China. Because of the paucity of herbarium collections and the deposition of type specimens in foreign herbaria, it is difficulty to study the genus Typha. Up to date, there is about7species in Sect. Bracteolatae in China. They are T. angustifolia L., T. angustata Bory et Chaub., T. davidiana (Kronf.) Hand.-Mazz., T. elephantina Roxb., T. pallida Pob., T. gracilis Jord. and T. minima Funk.. Its classification and geographical distribution have long been confused. For example, the classification、name and geographical distribution of T. angustifolia L., T. angustata Bory et Chaub. and T. domingensis pers., idengtification of T. minima Funk. and T. gracilis Jord., the existence of T. davidiana (Kronf.) Hand.-Mazz. in China or not and so on. Based on field collection, extensive literature material searching, combined with examining more than2000Typha specimens of China which now stowed in PE, IBSC, HIB, WH, CCNU, CDBI and so on, we make a taxonomic study of the gross-morphology and morphology characteristics of reproductive organs of Typha sect. Bracteolatae, discussed the variation of the related characters and classfication values, and a taxonomic revision of this sect was made together with neatening its geographical distuibution of China. The main results are as follows:1. Morphological characters and their classfication valuesGross-morphology characters including stems, leave-sheaths and leaves, female spikes characters of closely related species in Typha sect. Bracteolata are significantly different, can be important criterions in species distinguishing.1) Stem is robust in T. angustifolia, T. domingensis, T. elephantina Roxb., which is1.5-2.5m high or more, slender in T. minima, always not more than1m;2) Leave-sheaths and leaves:T. minima always only have sheath-like leaves or dimorphic, which are sheath-like leaves and linear leaves,1-4mm wide; there are only linear leaves in T. angustifolia, T. domingensis, T. elephantina,5-10mm wide. Leave-sheaths of T. angustifolia always auriculate, but both auriculate and tapering into lamina in T. domingensis, T. elephantina, leaves of T. elephantina are abaxially carinate, transverse section triangular, while the transverse section semicircular in T. angustifolia and T. domingensis;3) Female spikes:female spikes of T. minima3-5cm long, while in T. angustifolia, T. domingensis, T. elephantina is about8-25cm, and the spikes are light brown or medium brown in T. domingensis, but dark brown in T. angustifolia and T. elephantina.Morphology characteristics of the reproductive organs including the length of the anthers, morphology of the hairs of the axis, morphology of the female flowers’stigmas, morphology of the ovaries of the abortive flowers, color of the bracteoles and their morphology, morphology of the hairs on the stalk, and their length compaired with the bracteoles and the female flowers have important significance in distinguishing every species in Typha sect. Bracteolata, especilly in closely related species, and can be important criterions in distinguishing them.1) Male flowers:The length of anthers in T. angustifolia and T. domingensis are about1.6-2.3mm varies, hairs of the axis linear or have laciniate at apex, pollen-grains single, anthers in T. elephantina are about2.5mm long, hairs of the axis wedge, not forked, pollen-grains in tetrads; pollen-grains in tetrads in T. minima and have no hairs in axis;2) Female flowers:stigmas of the female flowers in T. angustifolia is linear, bracteoles spathulate to lanceolate varies, the same color as the stigmas, but less shorter or equilong more or less, hairs on stalk thickening at tip, with brown spots, the same length of the bracteoles or less shorter, shorter than stigmas, the ovaries of the abortive flowers flat at apex or slightly convex, always have brown spots; stigmas of the T. domingensis are linear too, bracteoles polymorphism, larger, shallower than satigmas, the same length of the hairs or less longer, shorter than stigmas, some of the hairs thickening at tip, without brown spots, the ovaries of the abortive flowers almost slightly convex at apex; T. elephantina have lanceolate stigmas, bracteoles linear, brown, less, the same length of the hairs, some of the hairs thickening at tip, the ovaries of the abortive flowers convex at apex, club-shaped. Stigmas of T. minima are linear or lanceolate, bracteoles spathulate, brown, hairs on stalk swelling or not at tip, in T. minima, hairs is equilong or shorter than the bracteoles, longer than the stalks, but shorter than sigmas, and the same length of the abortive flowers.2. Clarified the taxonomic confusion of T. angustifolia, T. angustata and T. domingensis, confirmed that most of the specimens identified as T. angustata in the main herbariums of China are T. angustifolia, and T. angustata described in FOC is not Typha domingensis Pers., and Typha domingensis is a new species distributed in China.3. Geographical distribution of T. elephantina of China which is from Menglian to Zhenkang in Yunnan now extend to Puge of Szechwan, and T. elephantina was found distributed in Szechwan China for the first time.4. Most of the specimens identified as T. gracilis in the main herbariums of China are similar to T. minima, whether there is T. gracilis distributed in China is still need further study.5. Taxonomic and geographical distribution of Typha sect. Bracteolatae in ChinaIntegrate all the results, we confirmed4species of Typha sect. Bracteolatae in China include T. angustifolia, T. domingensis, T. elephatina and T. minima. The plants of Typha are world wide in distribution, and is a cosmopolitan genus, but the areal-types of the every species are different. The areal-type of T. angustifolia and T. minima are cosmopolitan, which distribute in Europe, Asia, Africa and America and so on. T. angustifolia distributed in all the provinces of China, and Tibet is a new locality; Xinjiang, Northesat, North China are the main locacities of T. minima, Provinces of South China is fewer. T. domingensis is Pantropic, which is tropic Asia, Australasia (to New Zealand), Central and South America (or Mexio) disjuncted, but was found only distributing in Xinjiang, Gansu province. T. elephatina is tropic Asia to tropic Africa type. And distributed in Yunnan, Sichuan of China. Sichuan is the new locality.