Conspicuous Veins Research Articles

Hypericumliboense (Hypericaceae), a new species from Guizhou, China.

Hypericumliboense M.T.An & T.R.Wu, sp. nov. (Hypericaceae) is a newly described species found in the Maolan National Nature Reserve of Guizhou Province, where it grows in rocky habitats without soil on karst mountain tops. In this study, key morphological characters were compared between the new species and the other known Hypericum species of Hypericaceae. DNA sequences were extracted from the leaves of the new species, with nuclear gene sequences (ITS) generated to reconstruct phylogenetic trees and describe its phylogenetic position in relation to other species of Hypericum. Our results show that the proposed new species has the typical characteristics of the genus Hypericum in morphology being similar to Hypericummonogynum, but differing in its sessile and semi-clasped leaves, long elliptical to long circular leaf blades, thickly papery to thinly leathery, with entire and wavy leaf margins. The abaxial side of the leaves is covered with white powder, giving them a grey-white appearance. The main lateral veins of the leaves are 8-15-paired, and the midvein on both sides is convex. The main lateral veins and midvein branch are conspicuous, with tertiary venation forming a network on the leaf surface and appearing prominently sunken. The inflorescences are 1-3-flowered, with a large calyx and conspicuous veins. The molecular phylogenetic analysis (PP = 1.00) provided substantial evidence for the proposition of H.liboense as a new species within Hypericum. Morphological and molecular evidence is presented, corroborating the proposition of the new species, including a comprehensive account of the distinctive morphological attributes of H.liboense, along with its key distinguishing features from similar species.

Three new species of Xyris (Xyridaceae) from the Espinhaço Range, Brazil

Three new species of Xyris from Brazil are described and illustrated. Xyris nevata is characterized by bracts with conspicuous veins and a reddish androecium and gynoecium; X. pulchella also exhibits a reddish androecium and gynoecium, and is further characterized by its small size and terete to subterete leaf blades; X. rostrata has a turbinate spike and bracts with a rostrate-acuminate apex. Commentary is provided for each species on habitat, distribution, phenology and conservation status, and the new species are compared with morphologically similar species.

Host recovery and reduced virus level in the upper leaves after Potato virus Y infection occur in tobacco and tomato but not in potato plants.

In this study, the recovery phenomenon following infection with Potato virus Y (PVY) was investigated in tobacco (Nicotiana tobaccum), tomato (Solanum lycopersicum) and potato (Solanum tuberosum) plants. In tobacco plants, infection of severe strains of PVY (PVYN or PVYN:O) induced conspicuous vein clearing and leaf deformation in the first three leaves above the inoculated leaves, but much milder symptoms in the upper leaves. The recovery phenotype was not obvious in tobacco plants infected with PVY strain that induce mild symptoms (PVYO). However, regardless of the virus strains, reduction in PVY RNA levels was similarly observed in the upper leaves of these plants. Removal of the first three leaves above the inoculated leaves interfered with the occurrence of recovery, suggesting that the signal(s) mediating the recovery is likely generated in these leaves. In PVYN or PVYN:O but not in PVYO-infected tobacco plants, the expression of PR-1a transcripts were correlated with the accumulation level of PVY RNA. Reduced level of PVY RNA in the upper leaves was also observed in infected tomato plants, whereas such phenomenon was not observed in potato plants. PVY-derived small RNAs were detected in both tobacco and potato plants and their accumulation levels were correlated with PVY RNA levels. Our results demonstrate that the recovery phenotype following PVY infection is host-specific and not necessarily associated with the expression of PR-1a and generation of PVY small RNAs.

REVISIONS OF STATUS OF SOUTHWESTERN DESERT TREES AND SHRUBS

CALLIANDRA humilis Benth. var. reticulata (A. Gray) L. Benson, comb. nov. Acacia humilis Schlect. Linnaea 12: 567. 1938, not C. humilis Benth. in 1846. C. reticulata A. Gray, P1. Wright. 2: 53. 1853. Feuilleea humilis Kuntze, Rev. Gen. P1. 1: 188. 1891. F. reticulata Kuntze, loc. cit. 189. Anneslia reticulata Britt. Trans. N. Y. Acad. 14: 32. 1894. Anneslia reticulata Britt. & Rose, N. Amer. Fl. 23: 57. 1928. Primary leaflets in 1-2 or occasionally 3 or rarely 4 pairs; secondary leaflets 5 or commonly 7-11 mm. long, 2 or commonly 3.5-6 mm. broad, with often more than 2 conspicuous veins; leaflets, sepals, and pods glabrous or nearly so. Mostly in the yellow pine forests, the oak woodland, and the juniper-pinyon woodland at levels higher than the typical variety. Arizona from the Mogollon Rim southward to Santa Cruz and Cochise counties; New Mexico; Mexico. Type collections (1.) A. humilis, Pr. Raglam in pratis .... (C. Ehrenbergh). (2.) C. reticulata, Stony hills at the copper mines [Santa Rita], New Mexico; Aug. (1045.) Wright, GH. Corresponding characters of the typical variety have proved unstable. They are as follows: primary leaflets in 3-6 pairs; secondary leaflets 2.5-7 mm. long, 1.5-2.2 mm. broad or larger in occasional plants, with usually not more than two conspicuous veins; leaflets, sepals, and pods distinctly but not densely appressed-pubescent. Desert grassland and oak woodland at 3,500 to 5,000 feet elevation or rarely in yellow pine forests at as much as 7,000 feet. Arizona from Coconino County to Santa Cruz and Cochise counties; New Mexico; western Texas; Mexico.

Local Signature and Sensational Extensity.

Of the various theories aiming to account for local signs, two seem especially worthy of consideration: the sensory-complex theory, according to which sensations from spatial modalities are all respectively alike, but combine to give differences in local signs; and the sensory-element theory, which postulates a slight difference in every sensation by means of which associations of specific location are formed. In the present article reports are made of experiments in which 1 gr. and 10 gr. pressures were applied in one series to a conspicuous vein, and in another to a portion of the skin where no vein was in evidence. Localization of pressure was more accurate on a vein where the subcutaneous tissue is uniform than on other parts of the skin; and the weak stimuli were localized slightly more accurately than the strong. Both of these results would seem to argue against the complex theory and for the sensation-element theory: differences inhere in the elementary qualities of sensation and give rise to awarenesses of location; these minute differences, when combined in perceptual patterns, form the basis for awareness of size and extent. From Psych Bulletin 19:07:00452. (PsycINFO Database Record (c) 2012 APA, all rights reserved)