The Florida Jujube (Ziziphus celata), a Pleistocene Relic

Dry climate phases during the Pliocene and early Pleistocene fostered a desert scrub/grassland community that stretched from Florida to southern California.  Eventually, climate changed and extensive forests separated eastern and western populations of flora and fauna that live in dry sandy habitat.  This explains why there are eastern and western forms of diamondback rattlesnakes, tortoises, mole skinks, race runners, burrowing owls, brown headed nuthatches, scrub jays, kites, caracaras, harvester ants, digger bees, and many species of plants, including the jujube (Ziziphus sp.)

The Florida jujube (Ziziphus celata) is a shrub that grows to 6 feet high.  It prefers open sunny conditions prone to fire.

The Florida jujube formerly occupied sand scrub and the extensive longleaf pine/wiregrass savannahs.  But much of this area has been lost to citrus orchards and residential development.  The Florida jujube was first collected in 1948 and was thought to be extinct until a botanist discovered 6 clonal populations in 1987, 4 of which were located in cow pastures.  Cuttings were brought to Bok Tower Gardens where attempts are being made to propagate the species.  Most of the jujube bushes were found to be infertile because they were either clones or too closely related to each other to produce fruit.  Nevertheless, they had been able to survive by sprouting from roots and could live indefinitely as long as the roots weren’t dug up and destroyed.  Fortunately, new populations were discovered in the mid-1990s, increasing the known genotypes from 12 to 38.  Fruit with fertile seed is now being produced at Bok Tower Gardens.  The fruit is yellow and about 1/2 inch long.

Range map of Florida jujube.  Actually, it’s not this extensive.  It’s only found at a handful of sites within these counties.

Two western species of jujube, known as lotebushes, range from southern California to Texas.  They are closely related to the Florida jujube. The eastern and western forms were one ancestral species during the early Pleistocene.

The Florida jujube is closely related to 2 western forms, both known as lotebushes–Ziziphus parryi and Z. obtusfolia.  Before Z. celata became geographically isolated, they all shared a common ancestor.

Small animals and birds eat jujube fruit, but I suspect part of the reason this species has difficulty reproducing is because it’s  missing mastodons and ground sloths which spread the seeds in big piles of fertile dung.  Small animals and birds may eat around the seed and not spread it.  Jujubes are drought and fire tolerant.  They can resprout vegetatively following fire.  Fire suppression has undoubtedly contributed to its rarity as well.  Broadleafed trees will shade them out.

Cultivated jujubes are known as red dates in China.

Cultivated jujubes (Z. jujuba) are known as red dates in China where they are a popular fruit.  They are also eaten in the Middle East and other Far Eastern countries besides China.  I’ve never eaten a fresh jujube but dried ones taste like a cross between a dried apple and a raisin.  They’re not bad but nothing to get excited about.  Wild jujubes are edible but reportedly tasteless.

References:

Wecky, Carl

“Recent Development Boosts Recovery Prospects of Florida Ziziphus”

www.archbold-station.org

U.S. Fish and Wildlife Service pamphlet

“Florida Ziziphus: 5 year Summary and Evaluation”

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One Response to “The Florida Jujube (Ziziphus celata), a Pleistocene Relic”

  1. The Pre-historic Plant Composition of the Vero Beach, Florida Fossil Site | GeorgiaBeforePeople Says:

    […] in Florida, but he was wrong.  Jujubes were discovered growing in Florida in 1948.  (See: https://markgelbart.wordpress.com/2013/06/20/the-florida-jujube-ziziphus-celata-a-pleistocene-relic/)  This species was once more widespread.  The Florida population is a disjunct relic related to […]

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