Melampodium Leucanthum Research Articles

Plant Communities Suitable for Green Roofs in Arid Regions

In extensive green roof settings, plant communities can be more robust than monocultures. In addition, native plants might be hardier and more ecologically sound choices than non-native plants in green roof systems. The objectives of this research were to (1) compare the performance of plant communities with that of monocultures and (2) compare the growth of natives to non-natives in a simulated green roof setting. We conducted a two-year experiment at an outdoor site in a desert environment using four plant morphological types (groundcover, forb, succulent and grass). Native plants selected were Chrysactinia mexicana, Melampodium leucanthum, Euphorbia antisyphilitica, and Nassella tenuissima, and non-natives were Delosperma nubigenum, Stachys byzantina, Sedum kamtschiaticum and Festuca glauca. Plants were assigned randomly to either monoculture or community and grown in 1 m × 1 m custom-built trays filled with 15 cm of a proprietary blend of 50/20/30 lightweight aggregate/sand/compost (by volume). Native forb, Melampodium, in community had greater coverage for four of the five measurements in the first year over native forb in monoculture and non-native forb regardless of setting. Native forb coverage was also greater than non-native forb for three of the four measurements in year 2, regardless of setting. Coverage of native grass was significantly greater than non-native grasses throughout the experiment. Coverage was also greater for eight of nine measurements for native succulent over non-natives succulent. However, non-native groundcover coverage was significantly greater than native groundcover for seven of nine measurements. On 1 November 2016, relative water content (RWC) for succulents (p = 0.0424) was greatest for native Euphorbia in monoculture at 88%. Native Euphorbia also had greater RWC than non-native Sedum on 4 April 2017 (78%) and 4 July 2017 (80%). However, non-native Sedum had greater root length (6548 cm), root dry weight (12.1 g), and root-to-shoot dry weight ratio (0.45) than native Euphorbia. At the end of year 2, the relative growth rate (RGR) of native Euphorbia of 0.15 g·g−1·d−1 was greater than that of Sedum. While the native succulent had a smaller root biomass, its greater RWC and RGR would indicate it had better plant water status and grew faster than the non-native. The lack of differences in plant performance regardless of assignment to monoculture or community would imply that communities and monocultures are equally suitable for arid region green roofs.

Response of 10 Aster Species to Saline Water Irrigation

Asteraceae is one of the largest plant families with many important garden ornamental species. Salt tolerance of 10 aster perennials was evaluated in a greenhouse experiment, including the following: damianita (Chrysactinia mexicana), gregg’s mistflower (Eupatorium greggii), shasta daisy (Leucanthemum ×superbum ‘Becky’), blackfoot daisy (Melampodium leucanthum), lavender cotton (Santolina chamaecyparissus), aromatic aster (Symphyotrichum oblongifolium), copper canyon daisy (Tagetes lemmonii), four-nerve daisy (Tetraneuris scaposa), skeleton-leaf goldeneye (Viguiera stenoloba), and zexmenia (Wedelia texana). Plants were irrigated with nutrient solution at electrical conductivity (EC) of 1.2 dS·m−1 (control) or saline solutions at EC of 5.0 or 10.0 dS·m−1 (EC 5 or EC 10) for 5 weeks. Upon termination, growth parameters, foliar salt damage, relative chlorophyll content [Soil-Plant Analysis Development (SPAD) readings], and mineral concentration were measured. Gregg’s mistflower, skeleton-leaf goldeneye, and lavender cotton were the most salt-tolerant species with less reductions in shoot dry weight (DW) in both EC 5 and EC 10. Considering the relatively severe foliar salt damage (visual quality score of 3.1 and 2.7 at EC 5; 2.4 and 1.6 at EC 10) and mortality rate (10% and 40%) in EC 10, aromatic aster and zexmenia should be avoided where poor quality water may be used for irrigation. Gregg’s mistflower and skeleton-leaf goldeneye had relatively lower leaf sodium (Na) concentrations suggesting that both species can selectively exclude Na. Damianita and the four daisies, i.e., blackfoot daisy, copper canyon daisy, four-nerve daisy, and shasta daisy, were salt sensitive as evidenced by their greater growth reduction, foliar salt damage, and high Na and chlorine (Cl) accumulation in leaves, and should be avoided in landscapes where poor quality water may be used for irrigation.

Melampodium leucanthum, a source of cytotoxic sesquiterpenes with antimitotic activities.

A new tricyclic sesquiterpene, named meleucanthin (1), was isolated from an extract of the leaves and branches of Melampodium leucanthum, along with four known germacranolide sesquiterpene lactones, leucanthin-A (2), leucanthin-B (3), melampodin-A acetate (4), and 3α-hydroxyenhydrin (5). The chemical structure of 1 was elucidated by analysis of 1D and 2D NMR and mass spectrometric data. All compounds exhibited antiproliferative and cytotoxic efficacy against PC-3 and DU 145 prostate cancer cells, as well as HeLa cervical cancer cells, with IC50 values ranging from 0.18 to 9 μM. These compounds were effective in clonogenic assays and displayed high cellular persistence. They were also found to be capable of circumventing P-glycoprotein-mediated drug resistance. Mechanism of action studies showed that 4 caused an accumulation of cells in the G2/M phase of the cell cycle, and 2-5 caused the formation of abnormal mitotic spindles. These results suggest the cytotoxic effects of these germacranolides involve inhibition of mitotic spindle function, and it is likely that other mechanisms additionally contribute to cell death. These studies also demonstrate the possibility of isolating new, biologically active compounds from indigenous Texas plants.

Multiple Pleistocene refugia and Holocene range expansion of an abundant southwestern American desert plant species (Melampodium leucanthum, Asteraceae)

Pleistocene climatic fluctuations had major impacts on desert biota in southwestern North America. During cooler and wetter periods, drought-adapted species were isolated into refugia, in contrast to expansion of their ranges during the massive aridification in the Holocene. Here, we use Melampodium leucanthum (Asteraceae), a species of the North American desert and semi-desert regions, to investigate the impact of major aridification in southwestern North America on phylogeography and evolution in a widespread and abundant drought-adapted plant species. The evidence for three separate Pleistocene refugia at different time levels suggests that this species responded to the Quaternary climatic oscillations in a cyclic manner. In the Holocene, once differentiated lineages came into secondary contact and intermixed, but these range expansions did not follow the eastwardly progressing aridification, but instead occurred independently out of separate Pleistocene refugia. As found in other desert biota, the Continental Divide has acted as a major migration barrier for M. leucanthum since the Pleistocene. Despite being geographically restricted to the eastern part of the species' distribution, autotetraploids in M. leucanthum originated multiple times and do not form a genetically cohesive group.

`Plains' Blackfoot Daisy (Melampodium leucanthum)

Blackfoot Daisy (Melampodium leucanthum Torr. & Gray) is a common wildflower native to much of Arizona, New Mexico, Texas, Oklahoma, Kansas, and Colorado (Stuessy, 1972). This perennial subshrub is characterized by a tight mound of white composite flowers with golden centers and linear leaves. Correll and Johnston (1970) have reported that this attractive native plant flourishes in calcareous gravely soils. Indigenous to regions receiving 40 to 70 cm of annual rainfall, Blackfoot Daisy is found along roadsides in the high plains, shortgrass prairies, uplands, and on limestone outcroppings exhibiting disturbed soils of the southwestern U.S. (Borland, 1998). The long period of bloom and tolerance to the heat and drought of its native environment make this plant desirable for use in water-conserving landscapes. The unusual name Blackfoot Daisy is derived from the foot-shaped bract that surrounds the seed and turns black at maturity (Diggs et al., 1999). Blackfoot Daisy occurs as both a diploid and a tetraploid that are morphologically indistinguishable. Turner and King (1961) suggest the ploidy level does not appear to be influenced by geography or ecologic conditions. Populations of both ploidy levels have been found growing among each other. In 1996, we initiated a breeding project to identify wildflowers with potential for landscape use in demanding environments. Accessions with outstanding attributes were collected and selection trials conducted over several seasons. ‘Plains’ Blackfoot Daisy is the first formal release from our program. It was developed through 6 years of recurrent phenotypic selection for increased branching, compact growth habit and increased floral density. The unique, reflexed flower form is a distinguishing trait that helps to distinguish ‘Plains’ Blackfoot Daisy from other Melampodium leucanthum genotypes. Description

A guaianolide and four melampolides from Melampodium leucanthum

The aerial parts of Melampodium leucanthum from central Texas afforded a new guaianolide dilactone, which was named austinolide. Its structure was determined by spectral methods and the molecular structure was established by single crystal X-ray diffraction. In addition, two new 4βH-dihydrogermacranolides, 4-epimelnerins A and B, and two new melampolides, 3α-hydroxyenhydrin and 9-desacetoxyleucanthinin, were isolated. The aerial parts of a mountain population of M. leucanthum from Colorado afforded the known melampolides melampodin A acetate, leucanthin B and leucanthinin as well as 3α-hydroxyenhydrin. Peracid oxidation of leucanthinin provided the 4,5-monoepoxide derivative, the physical data of which were identical with 3α-hydroxyenhydrin.

Influence of Phosphorus on Nitrogen Fertilizer Requirement of Melampodium leucanthum (Blackfoot Daisy) Grown in Perlite-Vermiculite Medium

Abstract We determined the influence of N and P fertilizers on growth and tissue N concentration of container grown blackfoot daisy (Melampodium leucanthum Ton. & Gray), a resource-efficient native landscape herbaceous perennial for the southwestern United States. Regression equations derived from the data indicated that maximum growth could be obtained by application of 166 mg N/liter (ppm) in irrigation water if 30 mg P/liter were also applied. However, near maximum growth was obtained with 100 mg N/liter at the 30 mg P/liter level. Fifteen mg P/liter in irrigation water were not adequate for maximum growth. Tissue nitrogen concentrations in whole plants should be > 1.7% for growth not to be limited by N.

A PHOTOACOUSTIC STUDY OF MORPHOLOGICAL CHANGES OCCURRING IN PLANT TISSUE CULTURES ACCOMPANYING DIFFERENTIATION

Abstract— Melampodium leucanthum (Torr. and Gray) leaves were disinfested and explanted upon a callus inducing medium. Changes accompanying the process of differentiating into callus were monitored photoacoustically and included decreases in cuticular depth and pigmentation in the mesophyll layer.

Sesquiterpene and diterpene lactones from Melampodium leucanthum and the molecular structure of 4(5)-dihydromelampodin B

The aerial parts of Melampodium leucanthum afforded a novel diterpene-γ-lactone, 1,6,7-trihydroxy-17-acetoxymelcantholide, and two new sesquiterpene dilactones, 4(5)-dihydrocinerenin and 4(5)-dihydromelampodin C. The known melampolides, leucanthin A, melampodin A acetate, melampolidin and leucanthinin were also isolated. The structure determinations involved spectral and chemical methods. The molecular structure of 4(5)-dihydromelampodin B, determined by X-ray diffraction, is described.

Insect allelochemic effects of sesquiterpene lactones from Melampodium

The crude syrups of Melampodium americanum L. and Melampodium leucanthum Torr. and Gray and their principal sesquiterpene lactones, melampodin A and melampodinin A, significantly inhibit growth and deter feeding of the fall armyworm, Spodoptera frugiperda (J. E. Smith). Melampodin A and melampodinin A caused 2.3 × and 5.5 × greater S. frugiperda larval mortality, respectively, than glaucolide A, a sesquiterpene lactone with previously demonstrated insect allelochemic effects.

Two new germacranolides from Melampodium leucanthum and their reductive and oxidative rearrangements

Two new germacranolides from Melampodium leucanthum and their reductive and oxidative rearrangements

New melampolide sesquiterpene lactones from Melampodium leucanthum

The isolation of five germacranolide sesquiterpene lactones from Melampodium leucanthum Torrey and Gray (Compositae-Heliantheae) is reported. The structures of three new melampolides, melampodin-A acetate, leucanthin-A and leucanthin-B, have been determined by spectral methods and chemical correlations.

Carbon-13 and proton magnetic resonance study of the structure and conformation of a new germacranolide sesquiterpene dilactone

The structure of melampodin B, a new sesquiterpene dilactone isolated from Melampodium leucanthum, has been elucidated on the basis of physical properties, predominantly 13C and 1H n.m.r. data.

Melampodin, a new germacranolide from Melampodium leucanthum Torr. and Gray var. leucanthum(compositae)

The structure of melampodin, a new sesquiterpene lactone isolated from Melampodium leucanthum Torr. and Gray. var. leucanthum, has been elucidated on the basis of physical properties.

A CYTOTAXOXOMIC SURVEY OF MELAMPODIUM (COMPOSITAE‐HELIANTHEAE)

Turner, B. L.. and R. M. King. (U. Texas, Austin.) A cytotaxonomic survey of Melampodium (Compositae‐Heliantheae). Amer. Jour. Bot. 49(3): 233–26. Illus. 1962.—Chromosome counts are reported for individuals from 89 populations of Melampodium representing 26 species The genus is multibasic with x = 9, 10, 11, 12, 16 and 23. Chromosome numbers on a base of x = 10 characterize the section Melampodium while basic numbers of x = 23, 16, 12, 11 and 9 occur in the section Zarabellia. Melampodium camphoratum (n = 16) differs from all other species examined in having relatively small meiotic chromosomes. Only 6 of the 23 species are polyploid or have polyploid races. Melampodium leucanthum and M. cinereum have both diploid and tetraploid populations; the latter occur without any apparent morphological or geographical correlation and are probably autoploid in origin. A survey of the basic chromosome numbers known for other genera of the subtribe Melampodinae (12 of 22 genera) is presented. and it is suggested that x = 10 is the most probable basic number of the genus and subtribe.