Pinus clausa (Chapm. ex Engelm.) Vasey ex Sarg.
Reproductive Structures
Male cones
- occur in clusters at base of new shoots in lower crown
- 10 mm (0.4 in) long at maturity
- pinkish or purplish at maturity
- P. clausa var. clausa matures and releases pollen from late December
through mid-January
- P. clausa var. immuginata matures and releases pollen from late January
through February
Female cones
- occur in clusters of 2 to 5 near tip of new shoots
- yellowish-green at time of pollination
- 5 to 9 cm (2 to 3.6 in) long at maturity
- serotinous or non-serotinous
- dark brown to yellowish-brown
- ovoid-conic
- short-stalked
- apophysis dark brown
- umbo armed with short, sharp prickles
- persistent on branch 1 to many years
- P. clausa var. clausa bears both serotinous and non-sertinous cones
- P. clausa var. immuginata bears mostly non-serotinous cones
Seeds
- 5 mm (0.20 in) long
- dull black to gray
- triangular to oval
- wing 15 mm (0.6 in) long; glossy brown
According to Brendemuehl (1990) :
"Sand pine bears cones at an early age. It is
not unusual to find mature cones on 5-year-old trees. Occasionally
flowers, usually pistillate strobili, are produced by 9- to 10 month old
seedlings growing under nursery conditions. The two varieties of sand
pine differ appreciably in cone production, cone size, seed size, and
several other characteristics. An abundant crop of cones is produced by
Ocala sand pine almost annually. Choctawhatchee cone crops of similar
size are produced at 4- to 6-year intervals, with light crops in
intervening years.
"The majority of Ocala sand pine cones are serotinous: they remain closed when
mature and require heat to open. Consequently, seed dispersal is minimal. The
cones are very persistent and may accumulate in large numbers on a single tree.
"Seed dissemination of Choctawhatchee sand pine differs from that of Ocala
sand pine. The majority of Choctawhatchee cones open when mature and most of
the seeds are disseminated during September, October, and November. In
western Florida the prevailing winds during the fall are from the west and
northwest, and consequently seeds are distributed more evenly and to a greater
distance on the eastern and southeastern sides of stands of seed-bearing
age."