Nitrogen deficiency is a deficiency of nitrogen in plants. This can occur when organic matter with high carbon content, such as sawdust, is added to soil. Soil organisms use any nitrogen available to break down carbon sources, making nitrogen unavailable to plants. This is known as "robbing" the soil of nitrogen. All vegetables apart from nitrogen fixing legumes are prone to this disorder.
Echinacea is a genus of herbaceous flowering plants in the daisy family. It has ten species, which are commonly called coneflowers. They are found only in eastern and central North America, where they grow in moist to dry prairies and open wooded areas. They have large, showy heads of composite flowers, blooming in summer. The generic name is derived from the Greek word ἐχῖνος, meaning "hedgehog", due to the spiny central disk. These flowering plants and their parts have different uses. Some species are cultivated in gardens for their showy flowers. Two of the species, E. tennesseensis and E. laevigata, were formerly listed in the United States as endangered species; E. tennesseensis has been delisted due to recovery and E. laevigata is now listed as threatened.
Heliconia is a genus of flowering plants in the monotypic family Heliconiaceae. Most of the ca 194 known species are native to the tropical Americas, but a few are indigenous to certain islands of the western Pacific and Maluku in Indonesia. Many species of Heliconia are found in the tropical forests of these regions. Most species are listed as either vulnerable or data deficient by the IUCN Red List of threatened species. Several species are widely cultivated as ornamentals, and a few are naturalized in Florida, Gambia, and Thailand.
Solanum carolinense, the Carolina horsenettle, is not a true nettle, but a member of the Solanaceae, or nightshade family. It is a perennial herbaceous plant, native to the southeastern United States, though its range has expanded throughout much of temperate North America. The plant is an invasive in parts of Europe, Asia, and Australia. The stem and undersides of larger leaf veins are covered with prickles.
A leaf spot is a limited, discoloured, diseased area of a leaf that is caused by fungal, bacterial or viral plant diseases, or by injuries from nematodes, insects, environmental factors, toxicity or herbicides. These discoloured spots or lesions often have a centre of necrosis. Symptoms can overlap across causal agents, however differing signs and symptoms of certain pathogens can lead to the diagnosis of the type of leaf spot disease. Prolonged wet and humid conditions promote leaf spot disease and most pathogens are spread by wind, splashing rain or irrigation that carry the disease to other leaves.
Rudbeckia is a plant genus in the Asteraceae or composite family. Rudbeckia flowers feature a prominent, raised central disc in black, brown shades of green, and in-between tones, giving rise to their familiar common names of coneflowers and black-eyed-susans. All are native to North America, and many species are cultivated in gardens for their showy yellow or gold flower heads that bloom in mid to late summer.
Centaurea solstitialis, the yellow star-thistle, is a species of thorny plant in the genus Centaurea, which is part of the family Asteraceae. A winter annual, it is native to the Mediterranean Basin region and invasive in many other places. It is also known as golden starthistle, yellow cockspur and St. Barnaby's thistle.
Verbesina, many species of which have crownbeard as part of their common names, is a genus of flowering plants, in the family Asteraceae. It is a large genus of about 350 species.
Sphagneticola trilobata, commonly known as the Bay Biscayne creeping-oxeye, merigold Singapore daisy, creeping-oxeye, trailing daisy, and wedelia, is a plant in the tribe Heliantheae of the family Asteraceae. It is native to Mexico, Central America, and the Caribbean, but now grows throughout the Neotropics. It is widely cultivated as an ornamental groundcover.
Rudbeckia fulgida, the orange coneflower or perennial coneflower, is a species of flowering plant in the family Asteraceae, native to eastern North America.
Echinacea purpurea, the eastern purple coneflower, purple coneflower, hedgehog coneflower, or echinacea, is a North American species of flowering plant in the family Asteraceae. It is native to parts of eastern North America and present to some extent in the wild in much of the eastern, southeastern and midwestern United States as well as in the Canadian Province of Ontario. It is most common in the Ozarks and in the Mississippi/Ohio Valley. Its habitats include dry open woods, prairies and barrens.
Echinacea paradoxa, the yellow coneflower, Bush's purple coneflower, or Ozark coneflower, is a North American species of flowering plant in the family Asteraceae. It is native to southern Missouri, Arkansas, and south-central Oklahoma, It is listed as threatened in Arkansas.
Ratibida columnifera, commonly known as upright prairie coneflower, Mexican hat, and longhead prairie coneflower, is a perennial species of flowering plant in the genus Ratibida in the family Asteraceae. It is native to much of North America and inhabits prairies, plains, roadsides, and disturbed areas from southern Canada through most of the United States to northern Mexico.
Linaria dalmatica is a herbaceous, short-lived perennial plant native to western Asia and southeastern Europe that has become a weed in other areas. The family this plant now belongs to is the Plantaginaceae Family. Previously, it belonged to the Scrophulariaceae (Figwort) family. Its common names include Balkan toadflax, broadleaf toadflax, and Dalmatian toadflax. Linaria dalmatica has unique yellow flowers with an orange center that draw individuals to purchase them to display in their gardens. The distribution of L. dalmatica to North America can be attributed to use as a fabric dye, folk remedies and as an ornamental plant. However, it is now classified as a weed in both Canada and the U.S.A.
Lespedeza leptostachya is a rare species of flowering plant in the legume family known by the common names prairie lespedeza and prairie bush-clover. It occurs in the Upper Midwest region of the United States. The flowers are creamy-white to purplish and arranged into a narrow terminal spikes.
Croton glandulosus is a species of plant in the family Euphorbiaceae that has many common names such as vente conmigo, tooth-leaved croton, tropic croton and sand croton. The species's specific epithet, glandulosus, is due to the gland-like structures that appear at the end of the leaf stalk. C. glandulosus and various other species are found to be common weeds in gardens, crops, and lawns. This species in particular is highly problematic in crops such as cotton and peanuts in the Southeastern United States.
Verbesina virginica, known by the common names white crownbeard, or frostweed is a species of flowering plant in the family Asteraceae. It is native to the Southeastern United States, where it is found in calcareous soil, often in bottomland thickets and edges of woods.
Isopogon alcicornis, commonly known as the elkhorn coneflower, is a plant in the family Proteaceae and is endemic to part of the South Coast Western Australia. It is a low shrub with pinnately-lobed leaves and oval heads of hairy, white or pink flowers.
Verbesina alternifolia is a species of flowering plant in the family Asteraceae. It is commonly known as wingstem or yellow ironweed. It is native to North America.
