Life Sciences Commons^™

Western Ironweed: Research On Anatomy, Physiology, Life History And Control, M. K. Mccarty, C. J. Scifres

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

Western ironweed (Vernonia baldwini Torr.) is a member of a widespread and diverse genus. The genus is characterized by perennial herbs and shrubs. Weaver and Darland listed the increase of western ironweed, at one time sparsely distributed, as an indication of degeneration of the true prairie. They described the invasion, spread, and ultimate dominance of western ironweed in many pastures after the drought years. Weaver measured ironweed roots to a depth of 11 or 12 ft., and remarked that it was one of "the most abundant and worst weeds in native pastures derived from the true prairie." Research has …

The Genus Carduus L. In Nebraska, Marian Jane Fuller

Papers from the University Studies series (University of Nebraska)

The genus Carduus L., a member of the Compositae, consists of approximately 120 species native to Europe (Arenes, 1949; Mulligan and Frankton, 1954). Of these, C. acanthoides L., C. crispus L. and C. nutans L., have been introduced to North America, but only C. acanthoides and C. nutans have been reported in Nebraska.

A general description of the Nebraska members of this genus is as follows: annuals or biennials; herbaceous stems spiny winged; leaves lobed with spiny margins; heads solitary or clustered at end of branches; phyllaries imbricated, spine-tipped in many rows; florets tubular, perfect, usually purple, rarely white; cypsela …

Some Factors Affecting Germination And Seedling Growth Of Scotch Thistle, C. J. Scifres, M. K. Mccarty

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

Scotch thistle (Onopordum acanthium L.) is a native of Eurasia. Scotch thistle is found in the grasslands of central Nebraska, with heaviest infestations in Gosper, Dawson, and Valley Counties and limited occurrence in 18 additional counties. The Nebraska Unicameral declared it a noxious weed in 1965. This study measures the effects of some environmental factors on scotch thistle germination and seedling growth, and clarifies some of the interactions of these with inherent characteristics of the achene. The effect of achene coat, stratification, light, temperature, growth regulators, pH, depth of planting, salinity, germination inhibitors, and moisture stress were studied.

Germination And Early Seedling Development Of Musk And Plumeless Thistle, M. K. Mccarty, C. J. Scifres, A. L. Smith, G. L. Horst

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

The present study was conducted to determine the effects of some simulated environmental variables on the germination of musk and plumeless thistle achenes. The two species appear to occupy a somewhat similar role in the natural vegetation, and a direct comparison of germination characteristics was sought.

Life Cycle Studies With Musk Thistle, M. K. Mccarty, C. J. Scifres

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

Musk thistle (Carduus nutans L.) was added to the Nebraska noxious weed list in 1959. The objectives of this study were: (a) to determine the normal life cycle of musk thistle in Nebraska; (b) to determine the variations from the normal life cycle of musk thistle; and (c) to furnish a summary of the phenology for musk thistle in southeastern Nebraska. Observations are used freely throughout the text to describe morphological variations occurring within musk thistle that are not easily quantified.