Abstract Detail

Developmental and Structural Section

EDELMAN, SARA [1], RICHARDS , JENNIFER H [2].

Growth and morphology of a threatened, clonal, wetland palm, Acoelorrhaphe wrightii (Griseb. & H. Wendl.)H. Wendl. ex Becc.  .

The growth and morphology of rhizomatous, clumping palms, which are large, tropical, slow-growing species, has been understudied.  Acoelorrhaphe wrightii, paurotis palm, is native to the Caribbean basin, although it is threatened in its native habitat in southern Florida.  It grows in rounded clonal stands in wetland habitats.  The purpose of this study was to analyze growth and morphology of A. wrightii at the ramet and genet levels.  The study was conducted at Fairchild Tropical Botanic Garden and Montgomery Botanical Center, both in Coral Gables, Florida.  Plants studied were wild-collected from Florida (USA), Belize, and Mexico.  Stem height and circumference, lamina length, width and pinna number, and petiole length and width were measured on 2 or 3 ramets of 16 genets.  Growth rates were determined by recording leaf production and number of leaves present per ramet very 3 months for > 1 year on 2 ramets each for 39 genets.  Genet circumference, length, and width, and number of ramet tiers, plus number of living ramets > 0.5 m, were measured on 31 genets. Data were analyzed using Spearman rank correlations, linear regression and ANOVA.  Leaf length, width and pinnae number, as well as stem circumference, increase linearly with stem height < 0.5 m, then stabilize on taller stems.  Leaf production rate increases with stem height and varies with season, being greatest in summer and fall (average of 1-2 leaves/ month) and least in winter (1 leaf/3 months).  The number of leaves on a ramet increases with ramet height and leaf production rate.  Genets increase in size by producing horizontal rhizomes that turn up to form new vertical stems; this process appears to be episodic, as genets form concentric tiers of leafy stems, with the innermost tier tallest and the outermost tier shortest.  Both ramet and number of tiers increase with genet circumference.   While genet length and width expand equally (slope lnL X lnW = 0.9939), genets have oval shapes, perhaps as a result of early asymmetry in the branching process (intercept = -0.517).  This ex-situ data on A. wrightii growth and morphology provides an understanding of the architectural potential for this threatened species and will be used to compare with individuals in their native habitat.

1 - Florida International University and Fairchild Tropical Botanic Garden, Biological Sciences, Miami, FL, 33199, USA
2 - Florida International University, Department Of Biological Sciences, Miami, FL, 33199, USA

Keywords:
Arecaceae
Clonal growth
paurotis
Everglades
architecture.

Presentation Type: Oral Paper:Papers for Sections
Session: 26
Location: Pines North/Boise Centre
Date: Tuesday, July 29th, 2014
Time: 1:30 PM
Number: 26001
Abstract ID:255
Candidate for Awards:Katherine Esau Award