Rhododendron atlanticum

(Ashe) Rehder in E. H. Wilson and A. J. Rehder

in E. H. Wilson and A. J. Rehder, Monogr. Azaleas, 147. 1921 ,.

Common names: Dwarf azalea
Endemic
Basionyms: Azalea atlantica Ashe Bull. Charleston Mus. 13: 26. 1917
Treatment appears in FNA Volume 8. Treatment on page 468. Mentioned on page 458, 469, 472.

Shrubs, to 0.5–1 m, very strongly rhizomatous. Stems: bark ± smooth, not shredding; twigs scattered, multicellular eglandular-hairy (hairs unbranched) and/or stipitate-glandular-hairy, otherwise glabrous or, sometimes, sparsely unicellular-hairy. Leaves deciduous; petiole multicellular eglandular and/or stipitate-glandular-hairy, sometimes also unicellular-hairy; blade ovate to obovate, 2–5.5 (–6.5) × 0.8–2 (–3) cm, thin, membranous to chartaceous, margins entire, plane, ciliate, eglandular-hairy, apex acute to obtuse, often mucronate, abaxial surface glabrous or, rarely, sparsely scattered eglandular-hairy, sometimes sparsely (rarely densely) unicellular-hairy, adaxial surface (lustrous to dull), glabrous or sparsely scattered stipitate-glandular-hairy, sometimes also sparsely unicellular-hairy. Floral bud-scales glabrous or densely unicellular-hairy abaxially, margins usually unicellular-ciliate. Inflorescences 4–13-flowered; bracts similar to bud-scales. Pedicels 4–15 (–20) mm, eglandular and/or stipitate-glandular-hairy, otherwise glabrous or sparsely (rarely moderately) unicellular-hairy. Flowers opening before or with leaves, erect to horizontal, usually very fragrant and/or nearly mephitic-scented; calyx lobes 0.7–5.5 (–10) mm, marginal and scattered stipitate-glandular or, less commonly, eglandular-hairy, sometimes also unicellular-hairy; corolla white, usually flushed pink or rose (especially on tube), without blotch on upper lobe, funnelform, 23–58 mm, scattered, usually conspicuous, multicellular stipitate-glandular-hairy (hairs forming prominent band along middle of each lobe), otherwise glabrous or, sometimes, sparsely unicellular-hairy on outer surface, petals connate, lobes 8–24 mm, tube rather gradually expanded into lobes, 16–35 mm (equaling or longer than lobes); stamens 5, much exserted, ± unequal, 32–63 mm. Capsules borne on erect pedicels, 10–24 × 4–8 mm, usually densely stipitate-glandular-hairy, otherwise glabrous or densely unicellular-hairy. Seeds without distinct tails, flattened portion of testa well developed at each end; testa expanded, dorsiventrally flattened, ± loose. 2n = 26.


Phenology: Flowering spring.
Habitat: Moist pine flatwoods and savannas, sometimes in drier pine and/or oak forests, primarily in fire-maintained communities of the Atlantic coastal plain
Elevation: 0-200 m

Distribution

V8 915-distribution-map.gif

Del., Ga., Md., N.C., Pa., S.C., Va.

Discussion

Varieties and forms have been described within Rhododendron atlanticum (see E. H. Wilson and A. J. Rehder 1921; K. A. Kron 1993). Hybrids between it and R. canescens and R. periclymenoides are known. Rhododendron atlanticum is easily confused with the sympatric R. viscosum, which generally is taller, less rhizomatous, hairier, larger-leaved, and later-flowering (i.e., flowers appear after the leaves have expanded).

Selected References

None.

Lower Taxa

None.

... more about "Rhododendron atlanticum"
unicellular-hairy +, eglandular-hairy +, , +  and glabrous +
unicellular-hairy +, stipitate-glandular-hairy +, scattered +  and glabrous +
Mucronate (?) +, Acute (?) +  and Obtuse (?) +
Walter S. Judd +  and Kathleen A. Kron +
(Ashe) Rehder in E. H. Wilson and A. J. Rehder +
furrowed +  and smooth +
not flaky +
Azalea atlantica +
5.5 cm55 mm <br />0.055 m <br /> (6.5 cm65 mm <br />0.065 m <br />) +
2 cm20 mm <br />0.02 m <br /> (3 cm30 mm <br />0.03 m <br />) +
2 cm20 mm <br />0.02 m <br /> (5.5 cm55 mm <br />0.055 m <br />) +
ovate;obovate +
membranous;chartaceous +
thin;0.8cm;2cm +
scale-like +
0.55 cm5.5 mm <br />0.0055 m <br /> (1 cm10 mm <br />0.01 m <br />) +
unicellular-hairy +, eglandular-hairy +, , +  and stipitate-glandular +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.55 cm5.5 mm <br />0.0055 m <br />) +
1 cm10 mm <br />0.01 m <br /> (2.4 cm24 mm <br />0.024 m <br />) +
unicellular-hairy +, glabrous +  and stipitate-glandular-hairy +
0.4 cm4 mm <br />0.004 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
Dwarf azalea +
multicellular +
rose +, flushed pink +  and white +
unicellular-hairy +, , +, glabrous +  and stipitate-glandular-hairy +
rotate to crateriform campanulate cylindric globose or urceolate +
2.3 cm23 mm <br />0.023 m <br /> (5.8 cm58 mm <br />0.058 m <br />) +
Del. +, Ga. +, Md. +, N.C. +, Pa. +, S.C. +  and Va. +
0-200 m +
undifferentiated +
fusiform +
unicellular-hairy +  and glabrous +
mephitic-scented +  and fragrant +
pendulous +  and erect +
usually ovoid;cylindric +
Moist pine flatwoods and savannas, sometimes in drier pine and/or oak forests, primarily in fire-maintained communities of the Atlantic coastal plain +
multicellular +
terminal +  and axillary +
deciduous +
8mm +  and 24mm +
unicellular-ciliate +  and ciliate +
eglandular-hairy +
parietal +, axile +  and placentation +
tenuinucellate +  and unitegmic +
1.5 cm15 mm <br />0.015 m <br /> (2 cm20 mm <br />0.02 m <br />) +
unicellular-hairy +, glabrous +  and stipitate-glandular-hairy +
0.4 cm4 mm <br />0.004 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
scale-like +
reduced +
not sticky +
eglandular +  and multicellular +
unicellular-hairy +  and stipitate-glandular-hairy +
Flowering spring. +
4-5-carpellate +
in E. H. Wilson and A. J. Rehder, Monogr. Azaleas, +
distinct +
tailed +, flattened-ellipsoidal +  and fusiform +
unequal +
procumbent +  and prostrate +
creeping +  and sprawling +
peltate +  and capitate +
straight +
Undefined tribe Empetraceae +
distinct +
Rhododendron atlanticum +
Rhododendron +
species +
flattened +
expanded +
expanded +
1.6 cm16 mm <br />0.016 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
unicellular-hairy +, , +, glabrous +, stipitate-glandular-hairy +, eglandular-hairy +  and multicellular +
evergreen +, deciduous +  and perennial +
heterotrophic +, autotrophic +  and mycotrophic +