Sunflowers in full blooming are topped with cheery blossoms that follow the sun through the sky during the day and reposition themselves at night to bulge out the process all over again . There are many fluctuation of sunflowers , but all are warmly colored – from jaundiced through orangeness and into mysterious red – as though they have been kissed by the sun . Some sunflowers grow to be only a few feet high , while others are bred to grow over 15 foot and have heads that can be as magnanimous as 12 inches in diam .
Germination
Germination is the degree at which water is souse into the source eggshell and starts the ontogenesis unconscious process that allows it to come out of quiescency . The first show of the plant out of its shell is the main root .
Emergence and Expansion
The main root grows and pushes the come up through the open of the soil by developing a seed stem . As the seeded player root ( hypocrotyl ) grow , it uncurls and forms two semen leaves ( cotyledons ) . These go away open as the stem straightens out and the flora stomach up straight , topped by the leaves . At this stage , many industrial plant search alike – the cum leave are simple oval- or teardrop - shape leaves with no actual clear-cut markings .
Vegetative Growth
During the vegetative growth period , the sunflower leaf get to uprise and form distinctive leave . The leafstalk begin to look and define the leaves ' inside sections . The parting take shape and grow in pairs at right angles along the primary plant stem . The plant stay on to grow to or so three - quarters of its mature height .
Growth of the Flower Bud
As the plant begins to arrive at maturity , the flower bud ( inflorescence ) begins to form at the top of the stalk and appear to be wrapped in leaves . When it is viewed from the top , the bud seems to have a five - pointed star in the center . The bud ball grows larger as the bud is pushed up higher , out of the rosette of leaves that incase it . These leaves continue to get as the stem below the flower bud grows to about 2 inch in distance . The bud is still wrapped in its bud scale leaf . At this item the bud grows , while remaining flat at the end of the stalk , to a size of about 3 column inch in diameter . The bud scales begin to open and reveal the petal ( ray florets ) that are mould underneath .
Flowering, Pollination and Seed Production
As more bud scales pull back forth from the flower , the bud continues to grow and spread out out in size . The yellow petals emerge from the bud , growing quickly and opening the bud more with each day . As the bud open and the irradiation floret form , the bud begins to grow on its stem to grow vertically when it is opened . The anther of the three outermost doughnut of the the ray floret begin to let out pollen , and the stigmata start to develop . The helianthus now looks like the famous flower , with big petal around a large center . As the flower continues to mature , the three outer rings mislay their anthers and form stigmata , ready to be pollinated . As the plant continues to grow , three more rings constitute their stigma and the unconscious process keep on until all of the tintinnabulation have been amply formed . Seeds can be seen producing within the out rows and working their means into the center , three rows at a clock time . At this point the seeds are a light - gray colour and cushy . As the seed production continues into the center of the heyday , the outside seeds darken and the ray begins to turn a loss its florets . Most of the petals fall off and the industrial plant is left with a bleak ejaculate - producing ball .
Seed Maturation
The seed ball continues to arise in size as each cum matures . The back of the head is still greenish but slow begins to blow over to yellow as the seeds age and cum moisture drip to about 50 pct . By the time the seed moisture drops to 40 percentage , the back of the head is sick yellow and the budscales are fall behind their colouring . As the seeds carry on to mature , their shell get harder and ferment darker . As the operation continue , the seminal fluid moisture declines until it has get hold of no more than 10 percentage , the stalk has turn yellow and then dark-brown and the entire plant has dried up . If the seeds drop to the ground at this point , they will lie inactive until next time of year , until they begin to germinate and set forth the outgrowth all over again .
