Disentangling Polygala obovata Complex (Polygalaceae), with a Description of Three New Species for Brazil

Abstract— The morphology of the Polygala obovata complex, with a taxonomic revision of the current names, was studied, recognizing three new species of Polygala for Brazil. The new species, Polygala capitolensis, P. jardimii, and P. paganuccii, are described, along with their diagnostic characters and notes on taxonomy. Distribution maps and photographic plates, including a comparative morphology, are provided.

Taxonomic history, comparative morphology, and variation in Astrophytum myriostigma and its subspecies tulense (Cactaceae)

Astrophytum myriostigma subsp. myriostigma and subsp. tulense are distinguished by both vegetative and reproductive characters. The stem of the nominotypical subspecies is broad and depressed becoming broadly cylindrical in age, reaching a known maximum height of ca. 52 cm. In subsp. tulense, the stem is relatively slen-der and columnar and can reach a maximum height of ca. 90 cm. Both taxa show variation in the angle and profile of the ribs. In the nominotypical subspecies, the ribs are usually obtuse with a rounded or angular profile, or moderately acute with an angular profile. In subsp. tulense, the ribs are typically moderately to very acute with an angular profile. There are exceptions to these generalities. Both taxa have a modal number of five ribs, and both have the tendency to insert additional ribs with age, although the tendency seems more pronounced in subsp. tulense. The flower of the nominotypical subspecies differs from that of subsp. tulense in having a significantly larger mean perianth diameter (P <= 0.01), a significantly higher mean number of stigma lobes (P <= 0.05), and more tepal rows (3–5 vs. 1–3). The color of the tepals is pale yellow to whitish yellow in subsp. tulense, but brighter yellow or golden yellow in the nominotypical subspecies. The seeds of the nominotypical subspecies are significantly larger (P <= 0.01) than the seeds of subsp. tulense. Morphological variation was studied in nine populations of the subsp. myriostigma and six populations of the subsp. tulense. The nominotypical subspecies displays rib angle and rib profile differences among individual plants within a population. Plants with a depressed stem and obtuse, rounded ribs are predominant at some localities. At other localities, plants with more moderately acute, angular ribs are predominant, or at least common. Populations of subsp. tulense show individual variation in stem morphology. The stem varies from attenuated (tapered) to non-attenuated and from relatively slender (diameter ca. 20% of height) to relatively broad (diameter ca. 77% of height). The plants from near Mama León and adjacent localities in Tamaulipas, have very robust stems and are the least typical of the columnar subspecies. The rela-tionships of this population to other columnar populations warrant further study. The population near Las Tablas, San Luis Potosí, shows considerable variation in the stem and rib morphology. Some plants resemble the nominotypical subspecies whereas others are similar morphologically to subsp. tulense. The perianth diameter is intermediate between those of the two subspecies. The evidence suggests that this is an area of past or ongoing hybridization between the two taxa; the question of hybridization warrants further investigation. Attenuated and non-attenuated stems are the result of differential rates of vertical and lateral growth due to cellular activity in the apical and lateral meristems, respectively. The attenuated (tapered) stem is produced by a gradually increasing lateral growth rate which remains slower than the vertical rate. A non-attenuated stem is produced by the lateral growth rate exceeding the vertical rate early in development, then stabilizing at some point and not surpassing the vertical rate.

Morphology of the Pattern of Branching of the Aortic Arch in Syrian Hamsters (Mesocricetus Auratus)

The branching patterns of the aortic arches of 28 adult male and female Syrian hamsters (SH) were thoroughly examined under a stereomicroscope for the first time by using latex injection and corrosion casting to determine their general arrangements and morphological variations as well as their differences and similarities to other rodents and rabbits. Three major arteries, namely, the brachiocephalic trunk (BC), left common carotid artery (CC) and left subclavian artery (SA), originating from the aortic arch (AR), were uniformly noted in SH. The BC was consistently divided into the right SA and the right CA. SA in SH normally releases the internal thoracic, deep cervical, dorsal scapular, vertebral, superficial cervical and supreme intercostal arteries. The costocervical trunk typically consisted of supreme intercostal and internal thoracic arteries and a common trunk for dorsal scapular and deep cervical arteries. To comprehend the comparative morphology of the pattern of branching of AR more completely, our results were compared with previous studies in rodents and rabbits. (1) The general morphology of the great arteries from AR in SH was similar to that in mole rats, rats, mice, porcupines, and gerbils but was essentially different from that in rabbits, guinea pigs, red squirrels, ground squirrels, pacas and chinchillas. (2) The typical pattern of the branching of the subclavian arteries in SH was similar to that in guinea pigs, rats, and rabbits but was different from that of the reported rodents regardless of the origins of the bronchoesophageal and internal thoracic arteries and the composition of the costocervical trunk.

Comparative Morphology and Taxonomic Study of Chlorophytum sabiense And Two Other Species in the Genus Chlorophytum Ker-Gawl

Chlorophytum sabiense Omok. (a newly identified species in the family Asparagaceae) is unique, having multiple styles emerging from fused ovaries. This specialized character may be overlooked in conjuring up archetype for the genus Chlorophytum, since the genus is characterized by single and simple style. Comparative morphology and taxonomic study of Chlorophytum sabiense and two other species in the genus (Chlorophytum macrophyllum and C. stenopetalum) was carried out to appraise level of relatedness of Chlorophytum. sabiense and these existing members. Distribution of the three species is sympatric in the North Central part of Nigeria. Chlorophytum sabiense may be confused with either of the two species because of the attributes they have in common. Samples collected were raised in a garden and closely observed for duration of three years. Data collected from morphological studies were analyzed statistically. The three species show similarity in most of the vegetative characters studied, however Chlorophytum sabiense is distinguished from the two others having; multiple styles, smaller fruit size and shorter length of pistil relative to the stamen. Exceptional characteristics exhibited by Chlorophytum sabiense makes it stand out among species in the genus, while its close resemblance with its allies accounts for reason why it had escaped recognition for a long time.

Rheophytic Adaptation of Eurya Japonica Thunb. (Ternstroemiaceae)

Plants along rivers have narrow leaves to avoid the stress caused by the river&rsquo;s flow during flooding. Plants that have undergone such morphological leaf modifications to adapt to rivers are called rheophytes. Some populations of Eurya japonica Thunb. (Ternstroemiaceae) were grown on riversides so that the comparative morphology and anatomy of leaves between riverside and inland (control) populations could be examined to confirm their rheophytic speciation. Our morphological and anatomical analyses revealed that the leaf of E. japonica in the riverside populations was significantly smaller than that of the inland populations due to the decreased number of cells; therefore, the pattern of rheophytic differentiation in riversides was not the stenophyllization but the miniaturization of the leaf. Moreover, our results indicated that this species in the riverside populations had thicker leaves and higher density of stomata than those of inland populations, suggesting that E. japonica had been morphologically modified in response to the light and water environments along the river.

Comparative Morphology, Phylogeny, Classification and Evolution of Interstitial Habits in Microcambevine Catfishes (Siluriformes: Trichomycteridae)

The Microcambevinae are a catfish subfamily endemic to the Brazilian Atlantic Forest, comprising rare species with interstitial habits. Microcambevines have been classified in two genera, Listrura and Microcambeva, but the relationships among included intrageneric lineages are still poorly understood. The objectives of this study are to conduct a phylogenetic analysis integrating morphological characters and a multigene dataset, and to propose a classification better reflecting morphological diversity and phylogenetic relationships. Phylogenetic analyses combining 57 morphological characters and a 2563 bp molecular dataset generated similar phylogenetic trees with high support values for most clades, including the two genera and some intrageneric groups. Six morphologically distinctive infrageneric lineages, three in Listrura and three in Microcambeva, are classified as subgenera, as well as two new species are described. The morphological diversity here recorded integrated to available information about habitat indicate high level of divergent specialisation among lineages. The analyses indicate a series of convergent morphological traits between Listrura and other teleosts sharing a fossorial lifestyle, as well as specialised traits independently occurring within Listrura lineages. Similarly, a great diversity of morphological traits occurs convergently in Microcambeva lineages and other teleosts sharing psammophilic habits. This study shows that combining molecular and morphological data yields well-supported phylogenies, making possible to unambiguously diagnose clades and to establish evolutionary hypothesis on morphological evolution.