Page 8, April, 1984, PALMETTO
This is the fourth in a series of articles accumulations of sand, marl, and canopy, and within about 25 years, describing the Natural Communities defined
organic debris. The bare white rock Pine Rockland develops into by the FloridaNatural Areas Inventory (FNAI). This classification system must be viewed as a usually creates a very harsh, dry Rockland Hammock.
system of mental constructs imposed upon an environment, but during the wet Typical Pine Rockland shrubs include saw palmetto (Serenoa infinite variety of growing, changing, season pockets fill with water and intergrading, natural environments. Hence, humidify the environment. On some repens), roughvelvetseed (Guettarda more often than not, a given site will not precisely fit the classic description of the sites there may even be surface flow scabra), myrsine (Myrsine floridana), for a month or two each year. appropriatenatural community. Bypracticing poisonwood (Metopium toxiferum), wax myrtle (Myrica cerifera), comparing these descriptions to vegetation FNAI recognizes three types of
observed in the field, an interested naturalist blackbead (Pithecellobium Pine Rockland, all dominated by should be able to learn to identify plant South Florida slash pine (Pinus guadalupense), long-stalked stopper communities accurately and contribute valuable site information to conservation elliottii var. densa). Keys Pine (Psidium longipes), pineland
efforts. Rockland has an understory of *silver snowberry (Chiococca pinetorum), varnish leaf (Dodonaea viscosa), by Linda Conway Duever palm (Coccothrinax argentata), * brittle thatch palm (Thrinax tetrazygia (Tetrazygia bicolor), PINE
ROCKLAND microcarpa), and tropical shrubs. locustberry (Byrsonima cuneata), Pine Rocklands occur in southeast Dade Pine Rocklandshave a shrubby cockspur (Pisonia rotundata),
Florida on outcrops of Miami oolite tropical understory characterized by marlberry (Ardisia escalloniodes), sweet acacia (Acacia pinetorum), limestone. The ground surface is an extraordinary number of endemic
typically dissected and solution- species. Temperate species make up black torch (Erithalis fruticosa), pitted, often to the point the jagged the bulk of the understory in Big rhacoma (Crossopetalumrhacoma),
surface is termed "pinnacle rock." CypressPine Rockland. bustic (Dipholis salicifolia), and
These communities have no real soils. All of these are fire-maintained indigoberry (Randia acu/eata). Smaller plants include corky- The tree roots push into crevices in communities which normally burn
the rock and seek nutrients in small every three to ten years. Without fire, stemmed passionflower (Passiflora suberosa), coontie (Zamia pumila), hardwoods rapidly grow up into the yellowroot (Morinda royoc), piriqueta (Piriqueta caroliniana), pineland allamanda (Angadenia ~ ~ 6 berterii), diamond flower (Hedyotis nigricans), bracken (Pteridium aquilinum), Everglades musky mint (Hyptis alata var. stenophylla), Everglades partridge pea (Cassia ~ deeringiana), gopher apple (Licania ,- - :.::J""h~ -= =.-==- ,..~
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~ PALMEno, April, 1984, Page 9
michauxii), pineland croton (Croton *slender queen's delight (Stillingia the rare and endemic species. Some linearis), Galactia spp., large-flower sylvatica ssp. tenuis). species are found only in the Miami polygala (Polygala grandiflora), pine Rare species which occur in Pine area and much of the critical
pink (Bletia purpurea), Bahama senna Rockland as well as in other pineland habitat of the endangered
(Cassia bahamensis), and pineland communities include: * Bahama Key deer lies outside the Big Pine
brake (Pteris longifolia), and pine- sachsia (Sachsia bahamensis), * little refuge.
land fern (Anemia adiantifolia). strongback (Bourreria cassinifolia), ROCKLAND HAMMOCK
Prominent grasses are wiregrasses * beach creeper (Ernodea littoralis), Hardwood forest "hammocks"
(Aristida spp.), pineland broomsedge *coastal vervain (Verbena maritima), develop on rocklands protected from
t (Andropogon cabanisii), Schizachy- *white ironwood (Hypelate trifoli- fire. They may grow on virtually bare 11 rium semiberbe, and lopsided Indian ata), small-flowered lily-thorn rock, with roots entwined around boulders and reaching into crevices ~; grass (Sorghastrum secundum). (Catesbaea parviflora), holly-leaf
The following species are endemic rhacoma (Crossopetalum ilicifolium), for nourishment, but extended periods without fire can allow the to Pine Rocklands: *Blodgett's wild Big *necklacepod (Sophora
mercury (Argythamnia blodgettii), tomentosa), and Krug's holly (Ilex accumulation of several inches of organic soil. In South Florida suitable Brickellia mosieri, tragia (Tragia krugiana).
saxicola), Everglades painted leaf The remaining privately owned upland sites are usually islands
(Poinsettia pinetorum), and Pine tracts of Pine Rockland are in the surrounded by water or wetlands. partridge pea (Cassia keyensis), Miami and Big Pine Key areas where Sometimes a slightly lower "moat"
Chamaesyce conferta, * C. deltoidea they are severely threatened by rapid encircles the island, giving it an
var. adhaerens, *wedge spurge (C. residential development. There are additional buffer. (Scientists
deltoidea var. deltoidea), *Garber's extensive areas of Pine Rockland speculate that these features are the
spurge (C. garberi), C. pinetorum, protected in Everglades National result of a combination of factors
* Porter's hairy-podded spurge (C. Park, Big Cypress National Preserve, including windthrow of peripheral
porteriana var. keyensis), Porter's and the National Key Deer Refuge, trees, erosion by surface flows broom spurge (C. porteriana var. but these habitats are not ideal for all diverted by the hammock, reduced
periphyton growth and marl scoparia), *pineland jacquemontia
(Jacquemontia curtissii) , * Dichrom- .,"'-". , accumulation at the shady forest margin, and perhaps more rapid ena floridensis, *sand flax (Linum ,./ ."" .-,J. "'.,' .. .. arenicola), *tiny polygala (Polygala .:., '~.": " y;-. .,f dissolution of the limestone due to
smallii), *Digitaria pauciflora, . ...7:.:,.::::".' -- '.":'.'1 ; acidic runoff.) Although hammocks *pineland milk pea (Galactia ",.-.:., I do not normally flood, they are
pinetorum), Galactia smallii, ., :.!_-- ... '.~. dependent upon high water tables to * Tephrosia angustissima, * Florida ,.,. .-. keep their wetland firebreaks rl~m~ rlrass I TriDascumfloridanum\. effective and to maintain reservoirs in solution features to keep interior humidity high and temperatures moderate. The hammock's dense domed canopy is also critical to the interior microclimate. It not only fends off desiccating winds and frost, but it deflects storm winds and prevents extensive structural damage during hurricanes. There are Temperate Rockland Hammocks dominated by live oak (Quercus virginiana) and laurel oak (Q. hemisphaerica) in North Florida, especially in the Gainesville and Brooksville areas, but the classic isolated islands of tropical vegetation are found primarily in the Miami area, the Everglades, and the Keys. FNAI recognizes five different types in this part of the state. The Miami hammocks where live oak is mixed with tropical species are Miami Ridge Hammock. The tall forests of Jamaica
dogwood (Piscidia piscipu/a), mahogany (Swietenia mahagoni), gumbo limbo (Bursera simaruba), wild tamarind (Lysiloma latisiliqua), and other tropicals in the Upper Keys
continued next page I'dgt' 10, April, 1.,114,t'ALMt ITO ZIJzYJ!,iunl). ilnu spicewo()u many ecotones between communi- ties are simply vague boundaries ,Ire Keys Hammock lort'~(. (Calyptrclnthe.~ pallens). Coontie
The lower Keys' shorter (Zamia pumila), yellowroot (Morinda where species from the two mix, this
"scrubbier" forest of Jamaica royoc), dildo cactus (Cereus one is a distinct community with
dogwood with poisonwood pentagonus), The/ypteris kunthii, species of its own. Salt spray, wind, Oplismenus hirtellus, Lasiacis and occasional inundation by storm (Metopium toxiferum), seagrape (Coccoloba uvifera), *brittle thatch divaricata, and Oichanthelium tides make this too severe an
palm, etc., is Keys Hammock Thicket. commutatum are likely understory environment for a forest to develop,
If this is a sparse shrub community species. but the marine influences are not so
with cacti and other spiny, xerophytic Epiphytes may be abundant. Most extreme as to altogether prohibit
plants, it is considered Thorn Scrub. If common are resurrection fern terrestrial vegetation. The result is an it is a well-developed hardwood (Polypodium polypodioides), open rocky flat with stunted shrubs,
forest with an understory of cacti and needle-leaved airplant (Tillandsia succulents, and sparse herbaceous
agave and perhaps a few emergent setacea), soif-leaved wild pine plants rooted here and there in
(Tillandsia va/enzue/ana), and crevices and mounds of debris. *tree cacti (Cereus robinii), it is
classified as Cactus Hammock. The butterfly orchid (Encyclia tampensis). Littoral Rock Pavement is a technical
East Everglades, Pinecrest, and long Rare Rockland Hammock plants term which has been used for similar Pine Key areas each have a particular include *powdery catopsis (Catopsis environments in the Caribbean.
hammock type, but there is berteroniana), *cow-horn orchid FNAI distinguishes three Coastal
considerable species overlap and (Crytopodium punctatum), *night- Rock Barren Plant Communities. scented epidendrum (Epidendrum FNAI has not yet defined the criteria Halophyte Rock Barren is the most nocturnum), *banded wild pine for distinguishing them. common. This is the typical upper (Tillandsia flexuosa), * Florida royal
Typical Rockland Hammock zone of a rocky shore corresponding
woody species include white stopper palm (Roystonea e/ata), *Iignumvitae to the Beach Dune of a sandy coast.
(Eugenia axillaris), Spanish stopper (Guaiacum sanctum), *manchineel Saltwort (Batis maritima), glasswort (Eugenia foetida), mastic (Masticho- (Hippomane mancinella), *white (Salicornia virginica), and sea ironwood (Hype/ate trifoliata),
dendron foetidissum), inkwood purslane (Sesuvium spp.) sprawl * Florida thatch palm (Thrinax (Exothea paniculata), marlberry, among the rocks and buttonwoods (Conocarpus erecta) and scattered bustic, lancewood (Nectandra floridana), *prickly apple (Cereus small mangroves - usually black coriacea), strangler fig (Ficus aurea), gracilis), *fragrant wool-bearing cereus (Cereus eriophorus var.
wild coffee (Psychotria nervosa and P. mangrove (Avicennia germinans) fragrans), *tree cactus (Cereus sulzneri), crabwood (Ateramnus and white mangrove (Laguncu/aria
lucidus), black ironwood (Krugio- robinii), *cupania (Cupania g/abra), racemosa), but sometimes red
dendron ferreum), Simpson's *clusia (C/usia rosea), and mangrove (Rhizophora mangle).
stopper (Myrcianthes fragrans), *yellowheart (Zanthoxylum flavum). Cactus Barren generally occurs a Hammocks are extremely
myrsine, satinleaf (Chrysophyllum bit farther back from the shore on threatened by residential develop- extremely flat sites where there is an oliviforme), cabbage palm (Sabal ment, since they are frequently the
palmetto), blolly (Guapira discolor), exceptionally broad transition zone only spots of high ground within
hogplum (Ximenia americana), between ocean and hammock. This tracts of otherwise undevelopable
paradise tree (Simarouba g/auca) , commonly is characterized by
prickly lime (Zanthoxylum fagara), wetlands, and their big shady trees scattered cacti, agaves, and the
white torch wood (Amyris e/emifera), are attractive to homebuyers. Many following herbaceous species: blue fine hammocks have already been hackberry (Celtis laevigata), Guiana jacquemontia (}acquemontia plum (Drypetes laterifolia), milkbark destroyed, and others, such as the pentantha), flame acanthus
(Drypetes diversifolia), shortleaf fig great Brickell Hammock which once (Dicliptera sexangu/aris), Keys indigo extended for miles along Biscayne
(Ficus citrifolia), hold-me-back vine (/ndigofera keyensis), purple sida Bay, have been reduced to
(Pisonia aculeata), bitterbush (Sida ciliaris), fuzzy hibiscus (Hibiscus fragments. Public indignation is rising
(Picramnia pentandra) , wild dilly poeppigi), and Cyperus e/egans. over the devastation of the Keys
(Manilkara bahamensis), blackbead Cactus Barren may be so interspersed Hammock Forests on Key largo for (Pithecellobium guadalupense), with Thorn Scrub that the two cannot condominium construction, but the
catclaw (Pithecellobium unguis-cati), be meaningfully separated. botanically interesting Keys soapberry (Sapindus saponaria), The peculiar Big Pine Key site Hammock Thickets and Thorn Scrubs strongbark (Bourreria ovata), darling where *strumpfia (Strumpfia of the lower Keys may actually be in
plum (Reynosia septentrionalis), Gulf maritima) grows on a rock barren even more jeopardy becausethey are grey twig (Schoepfia chrysophy/- with pockets of reddish marl has Joides), West Indian cherry (Prunus not in the conservation spotlight. This been termed a Strumpfia Barren. is another situation where native
myrtifolia), saffron plum (Bumelia Coastal Rock Barren species plant enthusiasts need to speak out
ce/astrina), cinnamon bark (Canella include prickly pear (Opuntia dillenii for preservation of "scrubby"
winterana), Jamaica caper (Capparis and o. Triacantha), dildo cactus, cynophallophora), limber caper habitats that do not have the public agave (Agave decipiens), Spanish (Capparis flexuosa), princewood appeal of magnificent forest. bayonet (Yuccaa/oifolia), sea oxeye
(Exostema caribaeum), seagrape (Borrichia arborescens), *joewood (Coccoloba uvifera), coffee COASTAL ROCK BARREN (Jacquinia keyensis), *bay cedar colubrina (Colubrina arborescens), Between a Rockland Hammock or (Suriana maritima), marsh samphire soldierwood (Colubrina e//iptica) , Pine Rockland and a ro,-.ky shoreline (Philoxerus vermicu/aris), railroad *geiger trt'p (Cordia sebestena), there is often a tr;lnsition zone called vine (Ipomoea pes-caprae), sea daisy
myrtle-of-toe-river (Ca/yptranthes a Coastal Rock Barren. Whereas (Borrichia frutesens), chaff flower PALMmo, April, 1984, Page 11 (Alternanthera flavescens), * beach There are patches of. Halophyte creeper, Indian mallow (Abutilon Rock Barren scattered all through the permolle), love vine (Cassytha Keys and the Caribbean, but the filiformis) , Cienfuegosia yucatenen- other Florida types of rock barrens
sis, Keys dayflower (Commelina are critically endangered communi- erecta var. angustifolia), Oesmanthus ties. There is only one Florida site vigatus var. depress us, rockland dominated by *strumpfia, and morning glory (Evo/vulus convolvu- Conrad's Crazy Cactus Patch in long loides), hairy milk pea (Ga/actia Key State Park is the on Iy good Cactus
spiciformis), bladder mallow Barren of appreciable size remaining.
(Herissantia crispa) , white lantana (There are some nice pieces mixed in with Thorn Scrub in Cactus (Lantana involucrata), Christmas
berry (Lycium carolinianum), seaside Hammock on Big Pine Key.) This is
gentian (Eustoma exaltatum), marsh one of the Florida communities most
lavender (Limonium carolinianum), often destroyed out of ignorance; it is
coastal pimpernel (Samolus generally regarded as a worthless ebracteatus), Phyllanthus carolinien- "transition zone" in development sis ssp. saxico/a, portulaca (Portulaca plans, yet it is preferred habitat for o/eraceaand P. rubricaulis),and Sida many of the above species, a number
acuta. of which are endemic to the Keys. Grasses known to occur in this
community include salt jointgrass .Species flagged with an asterisk are on
(Paspalum vaginatum), Key grass the FNAI Special Plant list. Information on (Monanthochloe littoralis), green populations of these plants should be
sprangle top (Leptochloa dubia), sent to Suzanne Cooper, Botanist, at the
dropseed (Sporobolus virginicus), Florida Natural Areas Inventory, 254 East and Chapman's panicum (Panicum Sixth Avenue, Tallahassee, Florida 32303 ADDRESSCORRECTION chapmanii). (904/224-8207). The designation "N.E." was inadvertently left off Wendy than most. Their very size mitigates Zomlefer's street address in the pineland outside of Everglades the damage done by park-related review of her book in the last issue of National Park is still extant. Also, the activities. In a smaller park, such as The Palmetto. If the post office sent future of the pine lands in most of the Ron Ehman Park, the decision to back your order for her book, please above mentioned sites is not bright. build another baseball field could re-address your request as above. None of the DadeCounty parks,with result in the total destruction of the the exception of Navy Wells, is pineland. Park. As mentioned above,the park is administered for the sole purpose of Even Navy Wells, which is billed as not administered for the benefit of preserving the natural habitat. a pineland preserve, is not immune to the pinelands, and the amorpha Propertyowned by the school board damage. The Florida Keys Aqueduct receive no protection at al,. is, of course, being held for future use Authority, which runs a well field in It is imperative to act now if a as school sites. When used for school the middle of the pinelands, representative sample of the Rock sites, the pineland will be cleared. maintains a system of pipeline access Ridge pineland is going to be When a park, such as Larry and
roads through the pinelands. These preserved. The situation is most Penny Thompson Park, is adminis- roads provide a good site for invasion critical for the northern, temperate tered for purposes other than by exotic weeds. Unfortunately, half of the pinelands. Some cases pineland preservation, the pinelands Dade County is not prepared to require immediate habitat suffer drastically. This park is expend the necessary effort to keep acquisition to prevent the extinction primarily a campground and exotics out. of an endemic species. In particular,
recreation area. The pinelands at the Several of the endemic plants from the acquisition of land in the Cutler site were quite intact before the park the northern half of the Rock Ridge area is desperately needed to keep wasput in. However, in the designof pineland are on the edge of Po/ygallasmallii from extinction. The the park no attention was paid 10 extinction. Polyga/a smallii is known acquisition of the Deering Estate is protecting native vegetation since only from the pinelands in the Cutler also of the first priority. The pinelands that was apparently not felt to be area, none of which are protected around Cutler will have to serve as important. Areas of exotic plants from development in any way. Linum representative of the entire northern were allowed to remain undisturbed carteri var. carteri may already be Rock Ridge pinelands because while pinelands were cleared to extinct. The pinelands around its nothing is available farther north. provide parking and picnic areas. habitat in Coral Gables and South Second priority must be given to Scores of service roads were cut Miami have disappeared. Cham- species like Chamtlesyce adhaerens. through the pinelands. These roads aesyce deltoidea is found in most of This occurs in pinelands which are have become the focus for invasion the pineland remnants mentioned transitional between the northern by exotic weeds which now threaten above, but its close relative, Cham- and southern Rock Ridge pinelands. to destroy the remaining pinelands. aesyceadhaerens is not known from And, finally an effort mustbe madeto The spread of these exotics has been any area which is even slightly convince local government that allowed to proceed unchecked. Still,
protected. Amorpha crenulata is proper maintenance of those the pinelands at Larry and Penny nearly extinct as a wild species even pinelandsunder their jurisdiction is a Thompson Park are more protected though it occurs within Bird Drive necessaryresponsibility.