New species and a new record of Cycas (Cycadaceae) from Thailand

Two newCycas species from Thailand are here described.C. petraea andC. elephantipes. A noteworthy extensions of the range ofC. macrocarpa into southeastern Thailand is recorded. New taxa are illustrated, distributions of the new taxa are mapped, and a key to the species ofCycas in Thailand is provided.     

Circumscription and lectotypification of Cycas rumphii (Cycadaceae)

The misapplied nameCycas rumphii Miquel is demonstrated to be based on discordant elements, and is lectotypified by excluding the discordant elements of the protologue. Synonymy and misapplications of the name are provided.     

Scanning electron microscopy studies of cuticle micromorphology in Cycas L. (Cycadaceae)

Abstract

A scanning electron microscopy (SEM) study of Cycas cuticle characteristics was undertaken in order to expand our knowledge of microscopic characters not observable under light microscopy and to clarify unresolved affinitites among some species within the genus. Whole leaf and isolated cuticle specimens from the middle region of leaflets of greenhouse-grown plants of Cycas revoluta, Cycas rumphii, Cycas circinalis, Cycas media, and Cycas normanbyana were examined using SEM for interior and exterior features. Characteristics in common include hypostomy, hair bases on abaxial and adaxial surfaces, adaxial cells randomly arranged, adaxial exterior cuticle smooth, and stomata sunken to various degrees but stomatal pit always formed by two layers of epidermal cells. Stomatal complex is of the polyperigenous type. Stomata randomly dispersed and oriented, and except C. revoluta, are not contiguous. Stomata deeply sunken in C. revoluta, intermediate in C. rumphii and C. normanbyana, and less sunken in C. circinalis and C. media. Aperture between guard cells extends the entire stomatal length in C. rumphii and C. normanbyana, ～80% in C. circinalis and C. media, and ～50% in C. revoluta. Cuticular features of C. revoluta show the greatest difference from the other species in complex relief of exterior cuticle and interior cuticular structure of subsidiary cells; C. media and C. circinalis show close similarity to each other and their stomatal complex dimensions fall within the same unique cluster using principal component analysis under normalized variables. C. normanbyana and C. rumphii show the most similarity to each other in cuticular micromorphology. Stomatal complex dimensions of these two species fall into a second cluster that also includes C. revoluta. These data contrast with current taxonomy placing C. normanbyana synonymous to C. media.     

Bionomics and rearing of Miltotranes prosternalis (Lea, 1929) (Coleoptera: Curculionidae), a mutualistic cycad pollinator in Australia

Pollination is the crucial stage for reproduction and survival of plants, therefore knowledge about the bionomics of pollinators is often critical for plant conservation. Bowenia spectabilis (Cycadales: Stangeriaceae) is a CITES-protected cycad species endemic to the Wet Tropics Bioregion of Queensland, Australia. It is pollinated by a host-specific weevil species, Miltotranes prosternalis (Lea, 1929) (Curculionidae: Molytinae), which breeds in its male cones but also visits its female cones and pollinates them. The association between the cycad and the weevil is an obligate brood-site reward pollination system, in which the weevil is provided with food and a brood site by the plant in “return” for the service of pollinating it. To facilitate the knowledge of the natural history of this unique Bowenia pollinator, we developed a method for rearing mature larvae of M. prosternalis collected from the field in the laboratory. Furthermore, we summarize biological information of M. prosternalis gathered from previous studies and by firsthand observations in the wild and during rearing in captivity.     

Pollination of endangered Cuban cycad Microcycas calocoma (Miq.) A.DC.

Observations indicate that natural regeneration in the field of the cycad Microcycas calocoma (Miq.) A.DC. is extremely low, and has been so since early this century. It appears that populations of its insect pollinator are practically extinct, but some pollinator activity appears to be present in the largest population of Microcycas. Recommendations for identification and captive breeding of die pollinator are suggested as a complementary conservation strategy to a Microcycas propagation programme already established at the Cuban National Botanical Garden.     

泰国的苏铁

介绍泰国现存苏铁属10个种和2个亚种的分布与生境、形态特征及栽培技术要点,并介绍该属植物的授粉方式及虫害情况。     

海南岛苏铁属一新种

海南岛苏铁属（苏铁科）一新种,即三亚苏铁。     

Teucrium scabrum (Lamiaceae), a new species from Thailand

Summary   Teucrium scabrum (Lamiaceae), a new species from the western part of Thailand, related to T. quadrifarium Buch.-Ham. and T. viscidum Blume is described and illustrated, and a distribution map is provided.     

Gymnemopsis phuwuaensis (Apocynaceae,Asclepiadoideae), a new species from northeastern Thailand

A new species, Gymnemopsis phuwuaensis A. Kidyoo, has been discovered in northeastern Thailand and is here described and illustrated. An identification key to all species of the genus is provided. Photographs and a diagnostic comparison with the morphologically similar species G. calcicola Kerr, are also provided. Gymnemopsis phuwuaensis displays clear differences in form and color of the corolla as well as in size of bract and flower. A lectotype for Gymnemopsis pierrei is also designated.     

A new species of Cycas (Cycadaceae) from Karnataka,India

Cycas swamyi Singh & Radha, sp. nov. (Cycadaceae) is described and illustrated from Karnataka, India. This new species has been confused with Cycas circinalis L., which is found in the Western Ghats. However, on the basis of its habit, characteristic isotomous‐type dichotomous branching, pinnae anatomy, mega‐ and microsporophyll morphology and seed anatomy, it has been segregated from C. circinalis and is described here as a new species. The distribution and conservation status are also discussed. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 430–435     

德保苏铁回归种群繁殖特征的初步研究

以位于广西黄连山自然保护区的德保苏铁Cycas debaoensis回归种群为对象,从开花情况、传粉媒介、传粉昆虫数量、结实率、种子散播媒介和方式等方面,与德保苏铁模式产地的自然种群进行比较研究。结果表明,2016年回归种群与自然种群开花植株分别为149和49株,雄雌性比分别为3.96∶1和4.44∶1,开花植株占比分别为31.63%和19.52%,自然结实率分别为60.53%和86.53%。留存在雌株上的未脱落种子一年内的萌发率分别为53.13%和42.51%,一年内幼苗存活率分别为0和3.56%;因重力或外力(雨水、风和动物)搬运后散布的种子一年内的萌发率分别为42.51%和38.46%,一年内幼苗存活率分别为74.46%和88.26%。与自然种群一样,回归种群的有效传粉者为大蕈甲科甲虫,但传粉昆虫数量较少,每雌球花有23.5头甲虫。回归种群结实率低于自然种群,可能的原因是传粉昆虫数量相对较少。啮齿动物等外力对种子的散布能显著提高幼苗存活率并直接影响幼苗的定植与分布,对回归种群的补充与更新有重要影响。总体上,黄连山德保苏铁回归种群在自然界中已能顺利完成生长和繁殖进程,基本具备自我更新能力。     

Elettariopsis chayaniana(Zingiberaceae),a New Species from Eastern Thailand

A new species of Elettariopsis from eastern Thailand,E.chayaniana,is described and illustrated.     

Piperprotrusum (Piperaceae), a new species from southern Thailand based on morphological and molecular evidence

Piper protrusum Chaveer.& Tanee,sp.nov.is described and illustrated.It dominantly comprises three branching types with three different types of leaf blades,bases,and apexes.The critical distinguishing character is the protruded receptacle having a bract and nine stamens.Individual plants have been discovered in areas of Southern Thailand since 2004 without reproductive parts.The investigated sites were revisited several times,and an individual with flowers was finally found in July 2009.Phylogenetic analysi...     

Piper protrusum (Piperaceae), a new species from southern Thailand based on morphological and molecular evidence

Abstract Piper protrusum Chaveer. & Tanee, sp. nov. is described and illustrated. It dominantly comprises three branching types with three different types of leaf blades, bases, and apexes. The critical distinguishing character is the protruded receptacle having a bract and nine stamens. Individual plants have been discovered in areas of Southern Thailand since 2004 without reproductive parts. The investigated sites were revisited several times, and an individual with flowers was finally found in July 2009. Phylogenetic analysis of the new species and five similar species is carried out based on DNA fingerprinting. The genetic distances between the new species and five similar species range from 0.25 to 0.35, supporting new species designation. Molecular data conform to morphological data in validating that it is a new species. Additionally, its DNA barcodes have been provided for further identification in case the morphological data is unclear. The sequence data have been submitted to the GenBank database under accession numbers GU980898 (rpoB gene), GU980899 (rpoC1 gene), and GU980900 (psbA‐trnH region).     

Cone humidity is a strong attractant in an obligate cycad pollination system

1. Download : Download high-res image (265KB)
2. Download : Download full-size image

     

Development of seven novel EST-SSR markers from Cycas panzhihuaensis (Cycadaceae)

? Premise of the study: Cycas panzhihuaensis L. Zhou & S. Y. Yang is a vulnerable gymnosperm endemic to China, where its range represents the northernmost occupation of Cycas L. We developed EST-derived SSR markers to investigate its genetic diversity and population structure. ? Methods and Results: Based on the expressed sequence tag (EST) database for Cycas rumphii Miq., seven simple sequence repeat (SSR) markers were identified and screened in 55 individuals from seven wild populations of C. panzhihuaensis. Alleles numbered 2 to 5, and their observed heterozygosity and expected heterozygosity ranged from 0.0000 to 0.6545 and from 0.0535 to 0.6966, respectively. ? Conclusions: These new EST-SSR markers will enhance further studies of the population genetics of C. panzhihuaensis, allowing researchers to design reasonable conservation and management protocols.     

Differential fluorescent-banding patterns in chromosomes of four species of Cycas (Gycadaceae)

Similar karyotypes of In = 22 in Cycas circinalis, C. media var. basaltica, C. revoluia var. rewluta, C. revoluta var. taiwaniana and C. siammsis were compared with each other by using the CMA and DAPI fluorescent staining methods. Their four largest submedian-centromeric chromosomes each had a CMA band at the terminal region in common. Their 12 terminal-centromeric chromosomes commonly displayed CMA bands at the terminal region and the pericentric region. Two of the 12 terminal-centromeric chromosomes carried a CMA band somewhere in the interstitial region of the long arm. C. circinalis alone showed it at a relative position closer to the centromere. The other taxa showed it at a relative position near the terminal region. All of the chromosomes exhibited the DAPI dot at the centromeric region.