Search results
Results from the WOW.Com Content Network
They freely expel a myriad of these pollen grains, and only a small percentage of them ends up captured by the female floral structures on wind-pollinated plants. [3] They are typically 20–60 micrometres (0.0008–0.0024 in) in diameter, although the pollen grains of Pinus species can be much larger and much less dense. [1]
The flowers are wind-pollinated catkins. The fruit is an acorn , maturing about 18 months after pollination, 2–3 cm ( 3 ⁄ 4 – 1 + 1 ⁄ 4 in) long and 2 cm broad, bi-coloured with an orange basal half grading to a green-brown tip; the acorn cap is 1.5–2 cm ( 5 ⁄ 8 – 3 ⁄ 4 in) deep, densely covered in soft 4–8 millimetres ( 3 ...
Catkin-bearing plants include many trees or shrubs such as birch, willow, aspen, hickory, sweet chestnut, and sweetfern (Comptonia). [ citation needed ] In many of these plants, only the male flowers form catkins, and the female flowers are single ( hazel , oak ), a cone ( alder ), or other types ( mulberry ).
Other flowering plants are mostly pollinated by insects (or birds or bats), which seems to be the primitive state, and some plants have secondarily developed wind pollination. Some plants that are wind pollinated have vestigial nectaries, and other plants like common heather that are regularly pollinated by insects, produce clouds of pollen and ...
Flowers: Shinnery oak is monoecious with both female and male flowers borne separately on the same plant. [5] Male catkins are densely flowered, 1.5–3.8 cm long, and hang downward. Female catkins are 3–7 millimetres ( 1 ⁄ 8 – 1 ⁄ 4 in) long, contain 1 to 5 flowers, and are usually axillary on young shoots.
The flowers are wind-pollinated catkins produced in mid spring, maturing about 18 months after pollination; the fruit is a globose acorn, 1.5–2 cm (5 ⁄ 8 – 3 ⁄ 4 in) diameter, two-thirds enclosed in the acorn cup, which is densely covered in soft 4–8 millimetres (3 ⁄ 16 – 5 ⁄ 16 in) long 'mossy' bristles. [3] [4]
The small, solitary female flowers aggregate as the base of the erect male catkin, each subtended by a small bract. The flowers are wind or insect pollinated. [5] The seed is an acorn2–3.5 cm (3 ⁄ 4 – 1 + 1 ⁄ 2 in) long [6] and 2 cm in diameter, very similar to an oak acorn, but with a very hard, woody nut shell more like a hazel nut.
The male flower has 3–8 stamens; the female has a superior ovary with 3–7 carpels. Plane trees are wind-pollinated. Male flower-heads fall off after shedding their pollen. [citation needed] After being pollinated, the female flowers become achenes that form an aggregate ball. The fruit is a multiple of achenes (plant systematics, Simpson M ...