Studies in African Cyperaceae 32. Cyperus rheophyticus, sp. nov.

A new species, Cyperus rheophyticus , is described from seasonally submerged habitats in forest streams and rivers in South West Cameroon (500–1350 m). Cyperus rheophyticus is most similar to C. brevifolius ssp. brevifolius (syn. Kyllinga brevifolius ), a less slender species with a stronger rhizome, larger spikeiets and glumes with a spinose keel; also the anther and achene are larger in that species.     

Studies in African Cyperaceae 31. Cyperus microcristatus, a new species from Mt Kupe, Cameroon

Cyperus microcristatus , a new species from western Cameroon, is described and illustrated. Its taxonomic affinities are discussed. Cyperus microcristatus is most similar to C. densicaespitosus (syn. Kyllinga pumila ) in general appearance, but differs in its more perennial habit, its smaller spikelets and glumes, which are more prominently winged. Notes on habitat, ecology, distribution and conservation are provided. It is assessed as Critically Endangered, following IUCN (2001).     

Multiple origins of congested inflorescences in Cyperus s.s. (Cyperaceae): Developmental and structural evidence

? Premise of the study: The understanding of homoplasic structures becomes more relevant when they are complex and define large angiosperm taxa. Inflorescence architecture usually fulfills both features, as happens with Cyperus, a genus with two taxonomical subdivisions characterized either by alternative expressions of Kranz anatomy (C(3) or C(4)) or inflorescence shape (condensed or lax). Those subdivisions are not completely congruent because at least one of these presumed characters has evolved several times. We focused a SEM study on the inflorescence development in species with condensed inflorescences and different photosynthetic anatomy to test the possibility that condensed inflorescences of subgen. Anosporum (C(3) anatomy) have evolved independently from those of subgen. Cyperus (C(4) anatomy). ? Methods: Freshly collected inflorescences of C. entrerianus, C. eragrostis, C. oxylepis, and C. incomtus were studied using stereoscopic and scanning electron microscopy. ? Key results: Condensed inflorescences of Cyperus species with C(3) and C(4) anatomy had differences in structure and development: (1) mature structure, (2) position of second-order branching initiation in the first developmental stage of the inflorescence, (3) main axis development and elongation, and branching development, (4) types of ramifications, (5) phyllotaxis and symmetry. ? Conclusions: Results support multiple origins of condensed inflorescences in Cyperus, based especially on differences in timing during development and elongation of the main axis and branches, branching pattern and phyllotaxis. Structure and development may be the key to using inflorescence morphology as an external feature to distinguish large natural groups within Cyperus based on vegetative anatomy.     

Studies in African Cyperaceae 18. Two new subgenera of Cyperus

Two new subgenera are described and illustrated. Cyperus subgen. Protocyperus has an eucyperoid culm–anatomy and digitate clusters of spikelets. It contains about 100 species. Cyperus subgen. Fimbricyperus has a chlorocyperoid culm anatomy and many stalked spikes giving the habit of a slender Fimbristylis. It is based on a single species, viz. Cyperus subparadoxus Kükenthal.     

Phylogenetic relationships in Cyperus L. s.l. (Cyperaceae) inferred from plastid DNA sequence data

The phylogeny of Cyperus and allied genera has been reconstructed using cladistic analysis of plastid rbcL gene, rps16 intron, trnL intron, and trnL-F intergenic spacer sequence data in 40 species of tribe Cypereae. Cyperus s.s. as currently circumscribed is not monophyletic because ten cyperoid genera are embedded within it. Eucyperoid Cyperus species (with a C₃ anatomy, e.g. C. involucratus ) and the genera Courtoisina , Kyllingiella and Oxycaryum form a clade that is sister to a clade comprising chlorocyperoid species (with a C₄ anatomy, e.g. C. papyrus ) and the genera Alinula , Ascolepis , Kyllinga , Lipocarpha , Pycreus , Remirea and Sphaerocyperus . The position of two species is uncertain; C . tenellus is resolved in a clade together with Isolepis although with typical cyperoid spikelets, whereas I. humillima is not resolved near either Isolepis or Cyperus s . l . © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 138 , 145–153.     

Further notes on the cyperaceae of ceylon

Six species of Cyperaceae from Cyelon are taxonomically discussed. Described as new isCarex taprobanensis, an ally ofC. stramentitia. New combinations made areBulbostylis barbata ssp.pulchella, Cyperus, conglomeratus ssp.pachyrrhizus, andMachaerina rubiginosa ssp.crassa.     

Typification of names in Cyperus section Arenarii (Cyperaceae)

The typification of names in the genus Cyperus was done as part of an ongoing study of the section Arenarii. The latest monograph on the genus by Kükenthal (1936), accepted eight species in the section Bobartia (= Arenarii ), and a number of lower level taxa, which are treated here either as distinct species or synonyms. The taxonomic treatment of the core species, C. conglomerates Rottb., turned out to be especially confusing, which is reflected in the past identifications of the material, and consequently, has created wrong interpretations on the distributions. C. jeminicus Rottb. has similarly caused a lot of confusion. Currently we recognize 26 species in the section, with two subspecies in C. conglomerate. Most names in the section have not earlier been typified. Here we designate lectotypes for 33 names, three epitypes, and one neotype. Cyperus sections Arenarii Kunth and Hymenolepides Nees are typified also.     

Eudesmane derivatives from cyperus corymbosus

From the rhizomes of Cyperus corymbosus a new eudesmane sesquiterpenoid, isocorymbolone, was isolated besides the known compounds corymbolone and (+)-α-cyperone. The structure of the new compound was established by means of spectroscopic methods.     

山东莎草属植物果实形状及果皮微形态研究

利用扫描电镜对山东分布的18种莎草属植物的果实形状及果皮微形态进行了观察研究。结果表明,莎草属植物果实为椭圆状、倒卵状或卵状三棱形,顶端具柱状或锥状短喙;果皮微形态可分为:网-疣复合纹饰、网状纹饰、疣状纹饰和无规则突起纹饰4种类型;果皮微形态类型的划分与基于宏观形态特征的传统分类关联较小,但在该属形态相近的种间存在明显差异,可作为种间划分的依据。果皮微形态证据支持将水莎草属(Juncellus)、砖子苗属(Mariscus)和断节莎属(Torulinium)归入莎草属(Cyperus)的分类观点。     

Notes on tropical Africa Cyperaceae

New information relating to structure andor wider distributional records are given for four species of Cyperaceae indigenous to Zambia and/or Zimbabwe. Three are members of tribe Cypereae ( Sphaerocyperus erinaceus, Cyperus albopilosus, C. ciltochty-socephalus); one of Ficineae ( Isolepis trollii ). Tribal delimitation follows that of Goetghebeur (1986).     

Ecological studies on Cyperus difformis, Cyperus iria and Fimbristylis miliacea: three troublesome annual sedge weeds of rice

Cyperus difformis , Cyperus iria and Fimbristylis miliacea are troublesome annual sedges of rice grown in many countries. Laboratory and screenhouse experiments were conducted to determine the effects of temperature, light, salt and water stress, seed burial depth, and flooding time, duration and depth on germination, emergence and growth of these three species. Germination of all the three species was stimulated by light and warm fluctuating temperatures. Germination of C. difformis was influenced to a greater degree by increasing salt and water stress than C. iria and F. miliacea . In all three species, seeds sown on the soil surface gave the greatest percentage of seedling emergence, and no seedlings emerged from seeds buried in soil at depths of ≥1 cm. Flooding, although not continuous or deep, had a suppressive effect on emergence and growth of C. iria and F. miliacea . Intermittent flooding to shallow depths, however, was less effective in controlling C. difformis ; deep flooding was needed to suppress growth of C. difformis seedlings. When the flooding was delayed to 21 days after sowing, there was little growth reduction in all three species.     

A biogenetically important hydrocarbon from Cyperus scariosus

A new hydrocarbon isopatchoul-3-ene has been isolated from the essential oil of Cyperus scariosus. The structure and stereochemistry was assigned on the basis of spectroscopic and chemical data. Its biomimetic conversion to isopatchoulenol has been achieved.     

中国柱隔孢属的分类研究III.

短叶茳芏Cyperusmalaccensisvar.brevifolius和和三叶(鬼)针草Bidenspilosa上两个中国新记录种Ramulariacaricis和Ramulariaconcomitans,另外4个已知种的名称做了订正。     

中国柱隔孢属的分类研究III.*

短叶茳芏Cyperusmalaccensisvar.brevifolius和和三叶(鬼)针草Bidenspilosa上两个中国新记录种Ramulariacaricis和Ramulariaconcomitans,另外4个已知种的名称做了订正。     

A leptosidin glycoside from leaves of Cyperus scariosus

Phytochemical examination of the leaves of Cyperus scariosus resulted in the isolation and identification of a new glycoside, leptosidin 6-O-β-d-glucopyranosyl-O-α-l- rhamnopyranoside.     

Citric acid production from imumu Cyperus esculentus and Maize Zea mays

The production of citric acid from imumu Cyperus esculentus and maize Zea mays was carried out using Aspergillus niger. Hydrolysis of the substrates at 97°C produced a higher concentration of reducing sugars than at 40°C. The concentrations of citric acid were higher in unagitated and defatted cultures compared to agitated and undefatted cultures respectively.     

Differential cold tolerance, starch, sugar, protein, and lipid of yellow and purple nutsedge tubers

From measurements of viability after exposure of tubers to natural overwintering in the soil and 6 weeks exposure at 2 C, species cold tolerance of the tubers was ranked in decreasing order: yellow nutsedge `I' (Cyperus esculentus L.), an ecotype originating in Illinois; yellow nutsedge `G', an ecotype originating in Georgia; and purple nutsedge (Cyperus rotundus L.). The ratios of unsaturated-saturated fatty acids in tuber triglycerides, tuber polar lipids, and leaf polar lipids followed the same order as the cold tolerance rankings, with the most cold-hardy species having the highest ratios. Lipid content was less than 1% of dry weight in purple nutsedge tubers, but was from 5 to 7% in both yellow nutsedge tubers. Starch, sugar, and lipid contents increased significantly in the hardy yellow nutsedge `I' tubers during a 6-week exposure to 2 C, but did not change in the susceptible purple nutsedge tubers; only sugar increased in yellow nutsedge `G' tubers after this treatment. Protein content was not altered by the 2 C treatment in any of the tubers. Apparently, several factors involving starch, sugar, lipids, and fatty acids are related to the differences in tolerance to cold in these species.     

The taxonomic status of <Emphasis Type="Italic">Cyperus digitatus</Emphasis> var. <Emphasis Type="Italic">khasianus</Emphasis> (Cyperaceae)

Cyperus digitatus var. khasianus is re-instated and a lectotype for the variety and Cyperus hookeri are selected.     

The Effects of Temperature on Leaf Growth in Cyperus longus, a Temperate C4 Species

Plants of the C₄ sedge Cyperus longus L. were grown at 10, 20and 30 °C. An asymptotic growth curve, the Richards function,was fitted to growth data for successive leaves. The mean rateof leaf appearance was a linear function of temperature with0.014 leaves appearing per day for every 1 °C increase intemperature. The instantaneous relative rate of leaf extensionshowed a marked ontogenetic drift which was most rapid at 30°C and slowest at 10 °C. The mean absolute extensionrate for foliage had a temperature coefficient of 0.16 cm d^–1° C^–1 in the range from 10 to 30 °C. The durationof leaf growth was independent of leaf number at 10 and 20 °Cbut increased linearly with leaf number at 30 °C. The smalldifferences in relative growth rate at the three temperaturesresulted in large differences in foliage area produced at theend of a 30 d growth period. The final foliage areas at 20 and10 °C were 51 and 9% respectively of that at 30 °C. Cyperus longus, temperature, leaf growth, Richards function, growth analysis     

Constituents of the essential oil of Cyperus alopecuroides

We have investigated the constituents of the essential oil of Cyperus alopecuroides. Three new compounds, the hydrocarbon, (-)-eudesma-2,4(15)-11-triene, the sesquiterpene alcohol (-)-eudesma-3,11-dien-5-ol and the diterpene hydrocarbon (-)-dolabella-3,7,18-triene were isolated and their structure elucidated.