Sunflower
Sunflower
Scientific name: Helienthus anus L.
Local/Bangla name: “Surjamukhi”
Taxonomic Position According to Cronquist System (1988)
Kingdom | : Plantae |
Division | : Magnoliophyta |
Class | : Magnoliopsida |
Subclass | : Asteridae |
Order | : Asterales |
Family | : Asterceae |
Genus | : Helienthus |
Species | : H. anus |
Botanical Description of Sunflower
Habit: annual herb
Root: Usually tap roots but roots modified into tubers.
Stem: Erect or prostate, rarely climbing, some time woody
Leaf: Simple some time compound
Flower: Inflorescence head or capitulate
Involucre bract: The head or capitulum are surrounded by a whorl of bracts called the involecre thus producing a flower cluster resembling a single flower.
Pappus: Sepalsare modified into threadlike, hairy, or bristly structures, which surround the fruit and can stick to animal fur or be lifted by wind, aiding in seed dispersal.
Two types of flowers are present i.e. ray floret and disc floret
Ray floret-Present in the periphery, zygomorphic, ligulate, unisexual female flowers
Disc floret: Central position, bisexual, actinomorphic
Calyx: Calyx is modified into pappus or scale leaf
Corolla: Petal 5 or three tubular in disc florets or ligulate in ray florets, gamopetalous,aestivation is valvate.
Ray floret-unisexual, pistillate or neuter, zygomorphic, incomplete, sessile
Calyx-modified into pappus,
Corolla:Petal 5, rarely 4, ligulate, aestivation valvate.
Androecium:Absent.
Gynoecium-Carpel2, syncarpous, monocarpellary, ovary inferior, placentation basal.
Disc floret-Bisexual, complete, actinomorphic, sessile
Calyx: Sepal converted into pappus
Corolla-Petal 5, gamopetalous, tubular, aestivation valvate.
Androecium: Stamen 5, syngenesious, epipetalous
Gynoecium: Bicarpellary,syncarpous, ovary inferior with single locule, stigma two and bifid
Economic Importance
- Used as edible oil
- Used as ornamental plant
- Has medicinal virtue
Table 1. Sunflower Variety Developed by Bangladesh Agricultural Research Institute, Joydebpur, Bangladesh
Sl. No. | Name of Variety | Developed by | Year of Release | Growing Season | Yield |
1 | Kirony(D S-1) | Oil Seed Research Center | 1982 | Rabi and Kharif | 1.6-1.8 t/ha |
2 | BARI Surjamukhi-2 | Oil Seed Research Center | 2004 | Rabi and Kharif | 1.5-1.8 t/ha |