【摘要】 <正> 以前在我国东海地区广泛分布着的紫菜,据有关学者的研究,认为主要是圆紫菜(Porphyra suborbiculata Kjellm.)与长紫菜(Porphyra dentata Kjellm.)两种。我们自1958年3月开始进行浙江沿海一带的藻类调查,在调查中发现紫菜分布范围甚广,而且在种类方面也不仅限于以上所述两种,在采集中发现除以上两种以外,还有4到5种左右未曾论更多还原

【Abstract】 In the course of our investigation into the distribution of East sea algae,we have found,inaddition to Porphyra dentata Kjellm.and Porphyra suborbiculata Kjellm.previously described byfamous scientists,several species of porphyra never described before.In this paper,only one of them,Porphyra dentimarginata,is reported upon. CHARECTERISTICS:Its blades are composed of monostromatic cells;Its form is generally round,elliptic,or like flowers （cf.Pl.Ⅰ,Fig.1-5）;its colour is olive green or somewhat brown. Measures are:2-14 cm in height,2-9 cm in breadth,and 76-120 μ in thickness.Its base is discoid in shape.Its stipe is obscure;Its marginal portion consists of 2-6,sometimes more, rows of degenerated cells （cf.Pl.Ⅲ,Fig.3） which are light in colour;when it is young,they are imperceptible,but when sexual cells are mature,they fall off the blade.Their outside is furnished with jagged teeth （cf.Pl.Ⅲ,Fig.3） which are formed of 1-2 or at most 5 cells,sharp or blunt in form.Its vegetative cells are subrectangular with roundish corner in surface view （cf.Pl.Ⅲ,Fig.1,and Pl.Ⅱ,Fig.1）,and sometimes they are 16-28 μ broad,36-48 μ high in sectional view with a single stellate chromatophore （cf.Pl.Ⅲ,Fig.2）.Plants heterothallic, spermatangia situated just inside the degenerated marginal portion,consists of 128 spermatia,and its mode of division is A₄B₄C₈.Sporocarps scattered in the inside of the degenerated marginal portion,composed of 32 or 16 carpospores and its mode of division is ♀ A₂B₄C₄ or A₂B₂C₄ （cf.Pl.Ⅳ,1-4 and Pl.Ⅱ,Fig.2,3,6）. HABIT and GROWTH:Porphyra dentimarginata grows on rocks which are near the middle of the littoral region of sea.Its growing season lasts always from the winter of first year to March of the next year.After April,on account of the highly rising temperature,it gradually vanishes. SYSTEMATIC POSITION:According to the main characteristic of Porphyra dentimarginata -marginal portion with jagged teeth and degenerated cells-it belongs to the section marginata of genus Euporphyra.We recognize in it a form of progress,that is,an evolution from section Edentata to section Marginata.更多还原