Rhododendron canadense

(Linnaeus) Torrey in New York State

in New York State, Rep. Geol. Surv., 151. 1841 ,.

Common names: Rhodora
IllustratedEndemic
Basionyms: Rhodora canadensis Linnaeus Sp. Pl. ed. 2, 1: 561. 1762
Treatment appears in FNA Volume 8. Treatment on page 464. Mentioned on page 372, 455, 457.

Shrubs, to 1 m, rhizomatous. Stems: bark ± smooth to slightly shredding; twigs sparsely multicellular eglandular and shorter stipitate-glandular-hairy (hairs unbranched), also unicellular-hairy. Leaves deciduous; petiole multicellular eglandular and stipitate-glandular-hairy and unicellular-hairy; blade elliptic to oblong or obovate, 1–8.3 × 0.4–3 cm, thin, membranous to chartaceous, margins entire, usually ± revolute, sometimes plane, eglandular and unicellular-hairy, apex acute to rounded, abaxial surface eglandular and stipitate-glandular-hairy, also unicellular-hairy, (± glaucous), adaxial surface scattered eglandular and stipitate-glandular-hairy, also unicellular-hairy. Floral bud-scales unicellular-hairy abaxially, and often stipitate-glandular and eglandular-hairy, margins unicellular-hairy. Inflorescences sometimes fasciculate, 3–9-flowered; bracts similar to bud-scales. Pedicels 3–10 mm, (usually glaucous), usually sparsely stipitate-glandular-hairy, and sometimes also densely unicellular-hairy. Flowers appearing before or, sometimes, with leaves, erect to horizontal, fragrant; calyx lobes 0.4–1.5 mm, often scattered stipitate-glandular-hairy, sometimes also unicellular-hairy, margins glandular and/or eglandular-ciliate; corolla rose-purple to pink, rarely white, unspotted or red-spotted on upper 3 lobes, irregularly shaped, clearly 2-lipped due to very extensive connation of 3 upper lobes contrasting with 2 elongate, widely divergent lower lobes, 12–22 mm, glabrous or, sometimes, sparsely stipitate-glandular-hairy on outer surface, petals connate, upper lobe 3–8 mm, lateral lobes 12–22 mm (closely connate with upper lobe), lower lobes 12–22 mm, tube absent due to deep division between 2 lower lobes and between lateral and lower lobes; stamens 10, exserted, ± unequal, 9–20 mm. Capsules borne on erect pedicels, 0.7–1.7 × 0.3–0.6 mm, multicellular stipitate-glandular and eglandular-hairy and densely unicellular-hairy. Seeds with flattened tails; testa tightly appressed. 2n = 52.


Phenology: Flowering spring.
Habitat: Moist to dry, coniferous or mixed conifer-deciduous forests, thickets, open rocky areas, lake margins, bogs, swamps
Elevation: 0-1900 m

Distribution

V8 908-distribution-map.gif

N.B., Nfld. and Labr. (Nfld.), N.S., Ont., P.E.I., Que., Conn., Maine, Mass., N.H., N.J., N.Y., Pa., R.I., Vt.

Discussion

Rhododendron canadense is distinctive and is most closely related to R. vaseyi; together they constitute sect. Rhodora (Linnaeus) G. Don (W. S. Judd and K. A. Kron 1995). Rhododendron canadense is sometimes cultivated for its showy flowers.

Selected References

None.

Lower Taxa

None.

... more about "Rhododendron canadense"
unicellular-hairy +  and stipitate-glandular-hairy +
unicellular-hairy +  and stipitate-glandular-hairy +
Acute (?) +  and Rounded (?) +
Walter S. Judd +  and Kathleen A. Kron +
(Linnaeus) Torrey in New York State +
furrowed +  and smooth +
not flaky +
Rhodora canadensis +
1 cm10 mm <br />0.01 m <br /> (8.3 cm83 mm <br />0.083 m <br />) +
elliptic;oblong or obovate +
membranous;chartaceous +
thin;0.4cm;3cm +
scale-like +
unicellular-hairy +  and stipitate-glandular-hairy +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
multicellular +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.17 cm1.7 mm <br />0.0017 m <br />) +
unicellular-hairy +, eglandular-hairy +  and stipitate-glandular +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
Rhodora +
rose-purple +  and pink rarely white unspotted or red-spotted +
stipitate-glandular-hairy +, , +  and glabrous +
rotate to crateriform campanulate cylindric globose or urceolate +
extensive +
1.2 cm12 mm <br />0.012 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
N.B. +, Nfld. and Labr. (Nfld.) +, N.S. +, Ont. +, P.E.I. +, Que. +, Conn. +, Maine +, Mass. +, N.H. +, N.J. +, N.Y. +, Pa. +, R.I. +  and Vt. +
0-1900 m +
undifferentiated +
fusiform +
eglandular-hairy +, stipitate-glandular +  and unicellular-hairy +
fragrant +
erect +  and horizontal +
usually ovoid;cylindric +
Moist to dry, coniferous or mixed conifer-deciduous forests, thickets, open rocky areas, lake margins, bogs, swamps +
multicellular +
terminal +  and axillary +
1.2 cm12 mm <br />0.012 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
deciduous +
1.2 cm12 mm <br />0.012 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
eglandular-ciliate +, glandular +  and eglandular +
unicellular-hairy +
parietal +, axile +  and placentation +
tenuinucellate +  and unitegmic +
unicellular-hairy +  and stipitate-glandular-hairy +
0.3 cm3 mm <br />0.003 m <br /> (1 cm10 mm <br />0.01 m <br />) +
scale-like +
reduced +
not sticky +
eglandular +  and multicellular +
unicellular-hairy +  and stipitate-glandular-hairy +
Flowering spring. +
4-5-carpellate +
in New York State, Rep. Geol. Surv., +
distinct +
tailed +, flattened-ellipsoidal +  and fusiform +
Illustrated +  and Endemic +
unequal +
procumbent +  and prostrate +
creeping +  and sprawling +
peltate +  and capitate +
straight +
Undefined tribe Empetraceae +
flattened +
Rhododendron canadense +
Rhododendron +
species +
eglandular +  and multicellular +
unicellular-hairy +  and stipitate-glandular-hairy +
0.3 cm3 mm <br />0.003 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
evergreen +, deciduous +  and perennial +
heterotrophic +, autotrophic +  and mycotrophic +