Allium Onion

Allium species occur in temperate climates of the Northern Hemisphere, except for a few species occurring in Chile (such as A. juncifolium), Brazil (A. sellovianum), and tropical Africa (A. spathaceum). They vary in height between 5 cm and 150 cm. The flowers form an umbel at the top of a leafless stalk. The bulbs vary in size between species, from small (around 2–3 mm in diameter) to rather large (8–10 cm). Some species (such as Welsh onion A. fistulosum and leeks (A. ampeloprasum)) develop thickened leaf-bases rather than forming bulbs as such. Many alliums have basal leaves that commonly wither away from the tips downward before or while the plants flower, but some species have persistent foliage. Plants produce from one to 12 leaves, most species having linear, channeled or flat leaf blades. The leaf blades are straight or variously coiled, but some species have broad leaves, including A. victorialis and A. tricoccum. The leaves are sessile, and very rarely narrowed into a petiole.The terete or flattened flowering scapes are normally persistent. The inflorescences are umbels, in which the outside flowers bloom first and flowering progresses to the inside. Some species produce bulbils within the umbels, and in some species, such as Allium paradoxum, the bulbils replace some or all the flowers. The umbels are subtended by noticeable spathe bracts, which are commonly fused and normally have around three veinsThe third evolutionary line contains the greatest number of sections (seven), and also the largest subgenus of the genus Allium: subgenus Allium, which includes the type species of the genus, Allium sativum. This subgenus also contains the majority of the species in its lineage. Within the lineage, the phylogeny is complex. Two small subgenera, Butomissa and Cyathophora form a sister clade to the remaining five subgenera, with Butomissa as the first branching group. Amongst the remaining five subgenera, Rhizirideum forms a medium-sized subgenus that is the sister to the other four, larger, subgenera. This line may not be monophyletic

The majority of alliums are bulb-forming; however, there is a handful that grows from rhizomes, the way common chives (Allium schoenoprasum) do. These may never form any kind of bulb. Allium leaves tend to be long and strappy. Some—like the cork-screw allium—remain attractive all season, with a blue-green color that complements the flowers. Most early blooming alliums have foliage that tends to die-back early, as the plants go dormant for the summer.Alliums prefer a soil pH that is slightly acidic, at around 5.5 to 6.5. However, how well the soil drains is far more important than soil pH. Do not let the bulbs sit in damp soil, especially during their dormant season. If they remain wet for too long, they will rot. Adding a good amount of organic matter to the soil before planting will improve draining while allowing enough water to reach the bulbs.'Globemaster': Globemaster flower stalks are super-sized, can reach 3 to 4 feet tall, and topped with flowers that form a ball that’s 8 to 10 inches in diameter. Mount Everest is another imposing, tall allium. It’s not quite the size of Globemaster and it blooms in a creamy whiteAllium, commonly referred to as ornamental onions, are bulbous herbs that are characterized by their onion or garlic odor originating from their long, basal foliage. The genus contains hundreds of species and include the ornamental ones plus the garlic and onions we grow for food. Many are native to the northern hemisphere where they can be found growing in dry, mountainous regions. Although they are cultivated within the landscape, in nature ornamental onions can be found growing in forests and are present as a weed in disturbed areas. The genus contains approximately 700 species; most of which bloom between late spring and early summer.In 2019, Dr Anjula Pandey, Principal Scientist at ICAR-National Bureau of Plant Genetic Resources in New Delhi, together with scientists Drs K Madhav Rai, Pavan Kumar Malav and S Rajkumar, came across plants of this onion species, which they have named Allium negianum, in the border area of Malari village, in Chamoli district of Uttarakhand. It grows at 3,000 to 4,800 m above sea level and can be found along open grassy meadows, sandy soils along rivers, and streams forming in snow pasture lands along alpine meadows, where the melting snow helps carry its seeds to more favourable areas. With a narrow distribution, this newly described species is restricted to the region of western Himalayas and hasn’t yet been reported from anywhere else in the world, according to a blog post from Pensoft Publishers, which brings out the journal. (Source: indianexpress.com)