Les flores son azules o marielles. Les pontederiacees son natives de rexones tropicales y templaes, especialmente del Nuevu Mundu. Ensin hipanto. Anteres basifijas, introrses, de dehiscencia llonxitudinal o en Monochoria abrir por rajaduras o poros, tetrasporangiaes y ditecas.

Author:Tojacage Akisar
Country:Central African Republic
Language:English (Spanish)
Published (Last):3 April 2008
PDF File Size:11.94 Mb
ePub File Size:2.44 Mb
Price:Free* [*Free Regsitration Required]

Two new and peculiar species of Heteranthera are herein described. Heteranthera catharinensis is unique in the genus due to its glomerulate, many-flowered inflorescences, in which the flowers are restricted to the base and apex of the cincinni. It also possesses the biggest flowers in the H. On the other hand, Heteranthera pumila is described as the smallest known species of Pontederiaceae , with its dwarf stature, petiolate leaves with especially diminute blades, inflorescences 1—2— 3 -flowered, peduncle densely covered with glandular hairs, basal bract with glandular hairs at base, and smooth seeds, rarely possessing 7—9 inconspicuous longitudinal wings.

We present detailed descriptions, illustrations, comments, a distribution map, conservation assessments for the new species, and an identification key to the Brazilian species of Heteranthera s. Finally, we discuss inflorescence morphology and terminology in Pontederiaceae , characterizing it as thyrsoid. Perrier M. In Brazil, Heteranthera is currently represented by nine species i. The genus is especially diverse in the Atlantic Forest domain, where seven species are known to occur BFG Heteranthera was described based on Peruvian collections of H.

Since then, several different genera have been segregated or described to accommodate species which were considered aberrant from Heteranthera s. Eurystemon Alexander, Hydrothrix Hook. Perrier, and Zosterella Small. These genera were described mainly based on autapomorphic characters, such as vegetative differences e.

Several phylogenetic studies evidenced the paraphyly of Heteranthera Eckenwalder and Barrett ; Graham and Barrett ; Kohn et al. The genus is currently easily recognized by its non-pulvinate petiolate leaves, inflorescence reduced to a solitary cincinnus, stamens 1— 3, staminodes sometimes present, the lack of septal nectaries, and its unevenly trilobate stigma Pellegrini ; Pellegrini and Horn, unpublished data.

Despite Heteranthera being currently monophyletic and well circumscribed Pellegrini , some widely distributed taxa are still problematic. The main neotropical species complex is represented by H. Heteranthera reniformis s.

It is also known to be an aggressive weed, especially in rice fields around the world Ferrero ; Vescovi et al. Nonetheless, species identification is extremely difficult due to the poorly understood specific limits in this group. As part of our ongoing systematic studies in Pontederiaceae , based on extensive field and herbaria studies, we describe two peculiar new species segregated from H. The description and phenology of the species is based on herbaria, spirit, and fresh material, and is complemented by literature information.

The distribution of the species is based on herbaria materials, field data, and literature. The classification of the vegetation patterns follows IBGE The indumenta and shapes terminology follows Radford et al. GeoCAT Bachman et al. We update the number of species of Heteranthera in Brazil from nine to 11, including the number of species endemic to the country from one to three, and the total number of species in the genus from 14 to Both new species belong to the H.

We provide detailed morphological descriptions, comments, illustrations, and a distribution map for the new species, along with an identification key for the species of Heteranthera in Brazil. A morphological characterization and general comments are also provided for the H. Morphological characters differentiating the South American species of Heteranthera reniformis species complex.

States in bold represent unique or distinguishing characteristics for that species. Holotype of Heteranthera catharinensis C. Line drawing of Heteranthera catharinensis C. Illustration by M. Distribution map. It is unique due to its 3. Klein holotype: US barcode US! Herbs annual or short-lived perennials. Roots thin, delicate, unbranched, white.

Stems repent on the substrate or floating in shallow water, delicate, spongy, rooting at the nodes; internodes 1. Petiolate leaves distichously-alternate, distributed along the stem, floating to emergent; sheaths 2. Inflorescences axillary or apparently terminal, reduced to a solitary pedunculate cincinnus; peduncle 3.

Flowers bisexual, tubular, chasmogamous, sessile, enantiostylous; floral buds narrowly ellipsoid, light green, glabrous; perianth tube 5—7. Capsules not seen; persistent perianth base anthocarp smooth, medium brown. Seeds not seen. Reitz HBR! The epithet makes reference to the type locality, the state of Santa Catarina, Brazil. Heteranthera catharinensis is currently endemic to the state of Santa Catarina, in the Atlantic Forest domain Fig.

Is was found growing on open marshy areas and slow water environments within the Uruguay River watershed. Heteranthera catharinensis can be found in bloom in December.

Unfortunately, neither of the two currently known collections present mature fruits, thus fruiting time remains unknown. The inflorescence of H. The glomerulate appearance of the inflorescence i. The first one to three internodes are contracted, similarly to most species in the genus, thus making the basalmost flowers to be partially enclosed by the basal bract. Nonetheless, the following internode is considerably and consistently elongated, being commonly three to five times longer than the previous internodes.

The subsequent internodes are also contracted, giving the impression that the flowers are also congested at the apex of the inflorescence. This alternation between contracted and elongated internodes, produces a unique inflorescence architecture in the genus Fig.

Heteranthera catharinensis is morphologically similar to H. It is also superficially similar to H. Nonetheless, H. Aside from that, specimens of H. However, both species can be easily differentiated based on inflorescence architecture, and pubescence of the tepals and filaments.

Furthermore, H. Horn sp. Field photos of Heteranthera pumila M. Photographs A—E by M. Pellegrini, F by V. Line drawing of Heteranthera pumila M. F Uniseriate hair from the lateral stamen G Central stamen H Eglandular hair from the central stamen I Gynoecium, showing the stigma J Eglandular hair from the style K Detail of the inconspicuously winged seed, showing the persistent funiculus with raphid crystals.

Pellegrini, based on the holotype. Similar to H. It differs due to its diminute petiolate leaves [3. Almeida holotype: RB! Inflorescences axillary or apparently terminal, reduced to a solitary pedunculate cincinnus; peduncle 0. Flowers bisexual, tubular, chasmogamous, sessile, enantiostylous; floral buds narrowly ovoid, light green to lilac or pink, densely glandular-pubescent; perianth tube 4.

Capsule 5. Seeds 0. Lindeman et al. Faria et al. Dracena, margem do Rio do Peixe, fl. Bernacci et al. Aona et al. Igarapava, lagoa localizada na Fazenda Flor das Frutas, lado direito da pista no sentido Igarapava-Rifaina, na altura do km 16, fl. Paulo de Faria, fl. Souza et al.

Catharino et al. Coleman SP. Pereira-Noronha et al. Teodoro Sampaio, margem do lago ao lado da estrada Teodoro Sampaio-Planalto, ca. Km It is very likely that H. Nonetheless, we have been unable, so far, to find any vouchers from this state in the visited herbaria.

Heteranthera pumila blooms throughout the year, with flowering peaks during the wet season, and was found in fruit from September to October and from January to March.

On the other hand, its AOO is considerably smaller ca. It possesses the greatest energy generation potential in Brazil, with active hydropower plants, the largest being Itaipu, Furnas, Porto Primavera and Marimbondo.

Nonetheless, all the major rivers are currently saturated with hydropower plants, and new projects aim to occupy the smaller tributaries, in order to fulfil the growing energy demand in the region ANA Almost all the known subpopulations of H.





Espécie Eichhornia crassipes da Família Pontederiaceae


Related Articles