Dioscorea floridana

Bartlett

U.S.D.A. Bur. Pl. Industr. Bull. 189: 18. 1910.

IllustratedEndemic
Synonyms: Dioscorea villosa subsp. floridana (Bartlett) R. Knuth Dioscorea villosa var. floridana (Bartlett) H. E. Ahles
Treatment appears in FNA Volume 26. Mentioned on page 483.

Plants rhizomatous; rhizomes yellow, unbranched, horizontal, 0.5–1 cm or more diam., nodes articulate, each segment bearing 1 dark, contrasting, ± deltate scale leaf, scales brown and papery, caducous, each leaving dark, linear scar perpendicular to growing axis. Stems twining counterclockwise, ± polygonal to terete, 1–4 m, surface longitudinally grooved. Leaves alternate proximally (variation expected) and distally, 3–11 × 3–9 cm; petiole 3–8 cm, base not clasping; blade sometimes glandular, 7–9-veined, ovate-cordate to deltate, glabrous, margins entire or repand, apex acuminate. Staminate inflorescences (1–) 2–5 in leaf-axils, terminal, spicate to highly branched; cymes sessile, bearing 1–3 sessile flowers, bracteolate, internodes between cymes 2–5 mm, bracteoles linearlanceolate, ca. 1 mm; rachis to 30 cm, secondary axes to 15 cm, subtended by linearlanceolate bracts ca. 1–2 mm. Pistillate inflorescences borne singly, 4–20 or more-flowered, 4–25 cm, internodes 7–12 mm. Staminate flowers: perianth yellowish orange, rotate-campanulate to funnelform, 1–2 mm; tepals ± glandular, oblong, margins hyaline, apex (acute to) rounded or truncate; stamens in 2 equal whorls, inwardly curved; anthers ca. 1/3 length of filaments, thecae connate. Pistillate flowers: perianth as in staminate flowers; staminodes 6, differentiated into anthers and filaments, less than 1/2 size of fertile stamens. Capsules greenish gold, ovoid, obreniform, or oblong, 1.5–2.8 × 1.5–2.5 cm. Seeds 9–13 mm.


Phenology: Flowering late spring–mid summer; fruiting late summer.
Habitat: Edges of swamps, in hammocks, moist and dry (pine) forests and forest margins, sandy soils, lowlands
Elevation: 0–100 m

Discussion

Dioscorea floridana is undoubtedly a close relative of D. villosa, but because it is identifiable using characters that vary discretely, with states not manifest in plants occupying similar habitats outside of its range, I have chosen to retain it at the rank of species.

Selected References

None.

Lower Taxa

None.

"/3lengthoffilaments" is not declared as a valid unit of measurement for this property."-3timeslengthofperianth" is not declared as a valid unit of measurement for this property.

... more about "Dioscorea floridana"
tetrasporangiate +
truncate;rounded;acuminate +
Lauren Raz +
Bartlett +
0.2 cm2 mm <br />0.002 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
ovate-cordate +  and deltate +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
greenish gold +
1.5 cm15 mm <br />0.015 m <br /> (2.8 cm28 mm <br />0.028 m <br />) +
oblong;obreniform;oblong;obreniform;ovoid +
1.5 cm15 mm <br />0.015 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
long-appendiculate +
bracteolate +  and sessile +
Fla. +, Ga. +  and S.C. +
0–100 m +
0 size of fertile stamens;1/2 size of fertile stamens +
pistillate +, staminate +  and sessile +
1 +  and 3 +
3-winged +  and capsular +
loculicidal +
perennating +
Edges of swamps, in hammocks, moist and dry (pine) forests and forest margins, sandy soils, lowlands +
grouped +  and paniculate +
pistillate +, spicate +  and highly branched +
0.7 cm7 mm <br />0.007 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
cymose +, spicate +, unbranched +  and branched +
racemose +  and paniculate +
4 cm40 mm <br />0.04 m <br /> (25 cm250 mm <br />0.25 m <br />) +
3 cm30 mm <br />0.03 m <br /> (11 cm110 mm <br />0.11 m <br />) +
3 cm30 mm <br />0.03 m <br /> (9 cm90 mm <br />0.09 m <br />) +
repand +  and entire +
parietal +, axile +  and placentation +
yellowish orange +
rotate-campanulate +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
3 cm30 mm <br />0.03 m <br /> (8 cm80 mm <br />0.08 m <br />) +
Flowering late spring–mid summer +  and fruiting late summer. +
U.S.D.A. Bur. Pl. Industr. Bull. +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
perpendicular +
0 cm0 mm <br />0 m <br /> (15 cm150 mm <br />0.15 m <br />) +
compressed +
0.9 cm9 mm <br />0.009 m <br /> (1.3 cm13 mm <br />0.013 m <br />) +
Illustrated +  and Endemic +
differentiated +
winged +, smooth +, not +  and branched +
persisting +, or +  and renewed +
sometimes +  and glabrous +
than for more a single growing season +
less polygonal +  and terete +
100 cm1,000 mm <br />1 m <br /> (400 cm4,000 mm <br />4 m <br />) +
persistent +
distinct +
Dioscorea villosa subsp. floridana +  and Dioscorea villosa var. floridana +
Dioscorea floridana +
Dioscorea +
species +
0.3 cm3 mm <br />0.003 m <br /> (3 cm30 mm <br />0.03 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
divided +
expanded +