First finds of Acalypha australis L. and Euphorbia maculata L. (Euphorbiaceae) in Dnipropetrovsk region

A flora is a very plastic component of biovariety, especially on the urbanized territories with active development of transport, trade and different communications. From literary data on territory of Ukraine only from North America for the last 25 years about 30 new species that appeared quarantine plants got with various loads. In the flora of the Dnipropetrovsk area it is counted no less than 75 adentitious species, 102 species are cultivated and have a tendency to naturalization. In connection with the high level of urbanization the amount of adentitious and synanthropic species in a region increases constantly. Appearance of new species on any territory claims attention of researchers, in fact they can appear in a prospect dangerous for agricultural lands and natural ecosystems by reason of high competitiveness in the conditions of absence of natural wreckers. A base method for the study of regional flora is taking the inventory of species, it meens making lists of plants as a result of rout geobotanical researches. For determination of new species we used "Flora of the USSR" (1949), consultations were conducted with the known florists. Family Euphorbiaceae Juss. according to a determinant "Opredelitel… " (1987) is presented in our country by 6 genuses and 62 species. By us it is first found on territory of the Dnipropetrovsk area two representatives of Euphorbiaceae – Acalypha australis L. and Euphorbia maculata L. Both species are educed within the limits of Bagleyskiy district of Dniprodzerzhynsk. Acalypha australis is an one-year plant with a thin root and direct ramified ribbed stem, a kind is widespread in Manchuria, Korea, north China, Japan, America, in the former USSR – on Caucasus and Far East. His characteristic habitats are sands on the banks of the rivers, the clay are washed off slopes, near-by building, on trashes, in sowing. In the determinants of Ukraine Acalypha australis is absent, however on literary information first found in 1981 in Crimea, later in Odesa and near-by Luhansk. The population of Acalypha australis is educed on Dnipropetrovsk region to be under a supervision from 2006. First Acalypha australis was found here on a flower-garden in a private sector, where, probably, was brought with the seed of decorative plants. The quantity of individuals did not exceed two ten that grew on an area approximately one meter square. For 9 the area of population considerably increased and now presents no less than 200 м2. Shoots of Acalypha australis appears at the end of May, flowering takes place in July–August, fruiting – in August–September. A plant is weeded as ordinary weed, however it spreads successfully. To our opinion, it is related to the unpretentiousness of new kind to the terms of fertility and moisture of soil and high enough fruitfulness – from literary data to 100 seed from one individual. The representatives of the educed population grow on flower-gardens, along a fence and building, on beds among parsley, dill, strawberry, under a vine, in a hothouse with cucumbers. The domestic breeds of birds (chickens, geese) this kind do not eat. Euphorbia maculata is one-year old plant in a 10–20 cm high, with hard hairsprings. A kind takes place from North America, it as skidding is widespread in Europe, in the former USSR – in Western Transcaucasia and on Far East. His characteristic habitats are sands on the coasts of seas, embankments along roads. On territory of Ukraine Euphorbia maculata in determinants is absent, however on literary information led for Lviv and Crimea. The population of Euphorbia maculata on Dnipropetrovsk region was educed by us in 2010 near-by a recreation centre "Himik" (Dniprodzerzhynsk). A kind prevails on a wide sidewalk ground before a centre, sprouting on the small areas of soil between concrete flags on an area about 3000 m2. In a vegetable cover except Euphorbia maculata we discovered Polygonum aviculare L., Portulaca oleraceа L., Eragrostis minor Host. On information of workers of recreation centre "Himik", Euphorbia maculata grows here already no less than 6, thus these plants weed every summer. Existing in such terms, a kind appears very proof to trampling down and unpretentious to the food value and humidity of soil. Morphologically it is near to Polygonum aviculare and Portulaca oleraceа, from the last it easily differs by the presence of milk juice in all parts of plant. On flower-gardens and lawns that abut upon a sidewalk ground, Euphorbia maculata is not educed. The standards of herbarium of the registered new species are kept in the Scientific herbarium of the Dnipropetrovsk national university of the name Oles Gonchar (DSU). With the purpose of prognostication of adaptation possibilities and speed of distribution on Dnipropetrovsk Oblast of Acalypha australis and Euphorbia maculata we deem it wise to undertake scalene studies of the educed populations, in particular population structure, varying of morphological indexes, germination of seed, allelopathic activity in the conditions of steppe Pridneprove.