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.

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.

SUMMARIZATION
--	Rhizophora mangle red mangrove	Avicennia germinans black mangrove	Laguncularia recemosa white mangrove
Flowering Season	all year, but maximum in late spring and summer	spring and early summer	spring and early summer
Shape of Propagule	cigar, alrge green bean	oblong/elliptical, lima bean	flattened, pea green when fall, sunflower seed
Length of Propagule	15 cm	2 - 3 cm	less than .5 cm
Degree of Vivipary	extensive while on tree	intermediate?	"semi-viviparious" germination during dispersal
Obligate Dispersal	40 days	14 days	8 days
Root Establishment	15 days (either vertical or horizontal)	7 days	5 days
Viable Longevity	365 days	110 days	35 days
Seedling Mortality	lowest	intermediate	highest
Sucession	due to emgbryonic reserves, can establish under canopy and wait for tree to fall	need adequate light; need strand period of 5 days above tide	need adequate light; need strand period of 5 days above tide to hold soil