• How Is Blackjack Seed Suited To Its Method Of Dispersal
• How Is Blackjack Seed Dispersal Method
• How Is Blackjack Seed Dispersal Crops

The typical ‘blackjacks’ that attach themselves to passing animals and people radiate outwards as 1cm-long seeds crowned by two or three sharp awns. After fruiting, the plant dries out completely – even the roots become brittle. This is a mechanism to promote ‘zoochory’ – the dispersal of seeds through animal or human movement.

Seed Dispersal by Gravity Gravity is a force of attraction that exists among all the objects in the universe. As the fruits from the tree fall on the ground due to the force of attraction, they sometimes roll down to some smaller distance, get buried in the soil after a few days and germinate into a new plant. Seeds are widely dispersed through the fruits hook-like bristles that embed themselves in clothing and the fur of mammals and feathers of birds. They are also spread by wind, water and soil.

1. Blackjack is propagated by seed. Planting Seeds are sown early spring in a greenhouse and the seeds must be cov-ered. When the seedlings are large enough to handle, they must be picked out into individual pots. The sowing can be tried in mid to late spring. Blackjack plants grow fast; flowering starts 6 weeks after emergence.
2. Have you wondered what would happen if all the seeds grew close to each other? They will not get enough water, sunlight and space needed for their growth.

Mangroves have one of the most unique reproductive strategies in the plant world. Mangroves are viviparous (bringing forth live young), just like most mammals. Rather than producing dormant resting seeds like most flowering plants, mangroves disperse propagules via water with varying degrees of vivipary or embryonic development while the propagule is attached to the parent tree.

The red mangrove flowers mostly during the summer months. The long cigar shaped propagules are often found hanging on the tree all year long. The black mangrove flowers all summer long with the lima bean shaped propagules produced during late summer and early fall. The white mangrove flowers mid to late summer with small green pea shaped propagules produced a month later.

Once the propagule drops from the parent tree there is an obligate dispersal period which each species’ propagule must remain in the water. During this period embryonic development continues. For the red mangrove this dispersal period is the longest at 40 days. The black mangrove’s propagule must drift for at least 14 days. The white mangrove’s dispersal period is the shortest at 5 days, which also includes germination.

How Is Blackjack Seed Suited To Its Method Of Dispersal

If the propagule strands in a “favorable” area, there is an obligate stranding period before the primary roots and cotyledons (primary leaves) emerge. The red mangrove has the longest obligatory stranding period of 15 days. However, the propagule may be lying horizontally on the sediment or vertically “standing up” and may be covered by water during this time.

How Is Blackjack Seed Dispersal Method

How Is Blackjack Seed Dispersal Crops