2.1- Genus Sparganium + Overview Sparganium(Bur-reed) is agenusofflowering plants, described as a genus by Linnaeus in 1753. It is widespread in wet areas intemperateregions of both theNorthernand Southern Hemispheres.The plants are perennialmarsh plantsthat can grow to 3.5 m (depending on the species), withepicene flowers. It was previously placed alone in the family Sparganiaceae.Sparganiumis closely related to theTyphaceaeand theAPG III system(2009) includesSparganiumin that family. It has been determined from phylogenetic analysis to be the closest living relative of the genusTypha(cat-tail). + Characteristics Genus Sparganium, commonly known as the bur-reed, is a genus of aquatic plants of shallow marshes, ponds and streams. There are 9 species found in the United States and Canada.The stem, which may be floating or emergent, emerges from a buried rhizome, which like manywetlandplants, is dependent uponaerenchymato transport oxygen to the rooting zone. The leaves are strap-like. The flowers are borne in spherical heads, which bear either male or female flowers.The seeds may accumulate in the soil as dense seed banks, which allow the plants to regenerate during low water periods. Sparganium is an important component of aquatic and marsh vegetation in temperate to arctic regions. It provides food and cover for wildlife and waterfowl. + Taxonomy Genus Bur-reed, Sparganium, contains 26 species, of which 7 species grow in Finland. Species 1- Sparganium americanum- eastern North America 2- Sparganium androcladum- eastern North America 3- Sparganium angustifolium- Europe, Asia, North America 4- Sparganium confertum-Yunnan 5- Sparganium emersum- Europe, Asia, North America 6- Sparganium × englerianum - Germany 7- Sparganium erectum- Europe, Asia, North America 8- Sparganium eurycarpum-Russian Far East, Japan, North America 9- Sparganium fallax-East Asia, Himalayas,Sumatra,New Guinea 10- Sparganium fluctuans-Canada, northernUSA(New England,NY,PANJ,MI,WI,MN,WA) 11- Sparganium glomeratum- Scandinavia,Baltics,Belarus, Russia, China, Mongolia, Japan, Canada,Minnesota,Wisconsin 12- Sparganium gramineum-Scandinavia,Baltics, Russia, Japan 13- Sparganium hyperboreum- Alps, Subarctic (Europe, Russia, Alaska, Canada,Greenland) 14- Sparganium japonicum-Primorye, Japan,Korea 15- Sparganium kawakamii-Sakhalin, Kuril Islands 16- Sparganium limosum-Yunnan 17- Sparganium × longifolium- northern Russia 18- Sparganium natans- Europe, Asia, North America 19- Sparganium × oligocarpon - Siberia 20- Sparganium probatovae-Kamchatka 21- Sparganium rothertii- Siberia, Manchuria, Japan 22- Sparganium × speirocephalum - Finland 23- Sparganium × splendens- western Russia 24- Sparganium stoloniferum- temperate Asia 25- Sparganium subglobosum- East Asia, Himalayas, New Guinea, Australia, New Zealand 26- Sparganium yunnanense-Yunnan Source: Sparganium - From Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/Sparganium
+ Characteristics - Description Typhaleaves are alternate and mostly basal on a simple, jointless stem that bears the flowering spikes. The plants aremonoecious, withunisexual flowers that develop in denseracemes. The numerous male flowers form a narrow spike at the top of the vertical stem. Each male (staminate) flower is reduced to a pair ofstamensand hairs, and withers once thepollenis shed. Large numbers of tiny female flowers form a dense, sausage-shaped spike on the stem below the male spike. In larger species this can be up to 30 centimetres (12 in) long and 1 to 4 centimetres (0.39 to 1.57 in) thick. The seeds are minute, 0.2 millimetres (0.0079 in) long, and attached to fine hairs. When ripe, the heads disintegrate into a cottony fluff from which the seedsdisperse by wind. - General ecology Typhaare often among the first wetland plants to colonize areas of newly exposed wet mud, with their abundant wind dispersed seeds. Buried seeds can survive in the soil for long periods of time.Theygerminatebest with sunlight and fluctuating temperatures, which is typical of many wetland plants that regenerate on mud flats.The plants also spread by rhizomes, forming large, interconnected stands. Typhaare considered to be dominant competitors in wetlands in many areas, and they often exclude other plants with their dense canopy.In the bays of theGreat Lakes, for example, they are among the most abundant wetland plants. Different species of cattails are adapted to different water depths. Well-developedaerenchymamake the plants tolerant of submersion. Even the dead stalks are capable of transmitting oxygen to the rooting zone. AlthoughTyphaare native wetland plants, they can be aggressive in their competition with other native species.They have been problematic in many regions in North America, from the Great Lakes to theEverglades.Native sedges are displaced and wet meadows shrink, likely as a response to altered hydrology of the wetlands and increased nutrient levels. An introducedor hybrid species may be contributing to the problem.Control is difficult. The most successful strategy appears to be mowing or burning to remove the aerenchymous stalks, followed by prolonged flooding.It may be more important to prevent invasion by preserving water level fluctuations, including periods of drought, and to maintain infertile conditions. Typhaare frequently eaten by wetland mammals such as muskrats, which may also use them to construct feeding platforms and dens. Birds use the seed hairs as nest lining.