Chelone obliqua

Linnaeus

Syst. Nat. ed. 12, 2: 408. 1767.

Endemic
Treatment appears in FNA Volume 17. Treatment on page 59. Mentioned on page 57, 58.

Stems 25–180 cm. Leaves: petiole 3–20 mm; blade broadly elliptic to narrowly elliptic, 45–197 × 8–35 (–50) mm, base cuneate, margins once or twice-serrate, teeth 1–7 per cm, abaxial surface glabrous or pilose, rarely villous, adaxial usually glabrous. Cymes 38–86 mm; bracts 4–10 (–17) × 3–8 mm, ape× obtuse to acute or acuminate. Flowers: caly× lobes 7–10 × 3–7 mm, margins not or sparsely to densely ciliate; corolla dark-pink to red to purple, sometimes paler to white abaxially, tube 14–22 mm, abaxial lobes (10–) 12–19 × 5–15 mm, adaxial slightly keeled; palate yellow-bearded, rarely white-bearded; adaxial filaments (13–) 16–27 mm; staminode 4–12 (–14) mm, ape× white, rarely green or purple; style 16–34 mm.

Distribution

Ala., Ark., Ga., Ill., Ind., Iowa, Ky., Md., Mich., Minn., Miss., Mo., N.C., S.C., Tenn., Va.

Discussion

Varieties 3 (3 in the flora).

Chelone obliqua can be identified by its completely dark pink, red, or purple corollas with abaxial surfaces sometimes paler to white, yellow beards, and white staminodes. The species may be difficult to distinguish from other species of Chelone when rarely its beards are white or staminodes green- or purple-tipped. This may be due to rare intra- and interspecific hybridization (A. D. Nelson and W. J. Elisens 1999).

Chelone obliqua is allopolyploid (A. D. Nelson 1995; Nelson and W. J. Elisens 1999) and has a recombinant phenotype representing all three extant diploid species. Variation within C. obliqua reflects multiple independent origins (Nelson; Nelson and Elisens); some of the rare color variants could be due to this rather than hybridization (Nelson).

Chelone obliqua comprises two known chromosome races, 2n = 4x = 56 and 2n = 6x = 84. Tetraploids are found in the Blue Ridge Province; hexaploids are found in the Interior Low and Ozark plateaus as well as Central Lowland provinces and the Coastal Plain Province. Within each of these three physiographic provinces, distinct genotypes occur (A. D. Nelson 1995; Nelson and W. J. Elisens 1999; NatureServe, www.natureserve.org/explorer). Seven populations of C. obliqua were examined for this treatment, and it appears from this limited sample that the cytotypes might have regional ranges and minor morphological variation that support the varieties of C. obliqua as proposed initially by Pennell and Wherry and later treated as subspecies by Pennell. With the exception of caly× lobe margin indument, new characters are used to distinguish varieties because those used by Pennell had wide quantitative ranges or were highly variable qualitative characters.

Selected References

None.

Key

1 Staminodes 4–8(–12) mm; caly× lobe margins densely ciliate; Interior Low and Ozark plateaus, Central Lowland provinces. Chelone obliqua var. speciosa
1 Staminodes (6–)8–12(–14) mm; caly× lobe margins not or sparsely ciliate; Coastal Plain and Blue Ridge provinces. > 2
2 Abaxial corolla lobes (12–)15–19 mm; mid-cauline leaf blades 53–80(–117) mm; Coastal Plain Province. Chelone obliqua var. obliqua
2 Abaxial corolla lobes 12–15(–16) mm; mid-cauline leaf blades (60–)80–197 mm; Blue Ridge Province. Chelone obliqua var. erwiniae
... more about "Chelone obliqua"
1 cm10 mm <br />0.01 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
1.2 cm12 mm <br />0.012 m <br /> (1.9 cm19 mm <br />0.019 m <br />) +
ovate;rounded +
0.5 cm5 mm <br />0.005 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
villous +, pilose +  and glabrous +
1.3 cm13 mm <br />0.013 m <br /> (1.6 cm16 mm <br />0.016 m <br />) +
1.6 cm16 mm <br />0.016 m <br /> (2.7 cm27 mm <br />0.027 m <br />) +
Allan D. Nelson +
Linnaeus +
alternate +, opposite +, whorled +, helical +  and subopposite +
cuneate +
elliptic +  and elliptic to narrowly +
3.5 cm35 mm <br />0.035 m <br /> (5 cm50 mm <br />0.05 m <br />) +
4.5 cm45 mm <br />0.045 m <br /> (19.7 cm197 mm <br />0.197 m <br />) +
not leathery +  and not fleshy +
0.8 cm8 mm <br />0.008 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
1 cm10 mm <br />0.01 m <br /> (1.7 cm17 mm <br />0.017 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (1 cm10 mm <br />0.01 m <br />) +
acuminate;acute +
0.3 cm3 mm <br />0.003 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
paler +  and white +
spikelike +
3.8 cm38 mm <br />0.038 m <br /> (8.6 cm86 mm <br />0.086 m <br />) +
Ala. +, Ark. +, Ga. +, Ill. +, Ind. +, Iowa +, Ky. +, Md. +, Mich. +, Minn. +, Miss. +, Mo. +, N.C. +, S.C. +, Tenn. +  and Va. +
drupe-like +
curved +  and straight +
pubescent +  and villous +
1 +  and 4 +
persistent +  and deciduous +
serrate +  and dentate +
entire +  and subentire toothed or lobed +
2 times-serrate teeth +
axile +  and parietal +
basal +, apical +  and superior +
tenuinucellate +, unitegmic +  and hemitropous +
campylotropous +, hemianatropous +  and anatropous +
white-bearded +  and yellow-bearded +
5 +  and 4 +
0.3 cm3 mm <br />0.003 m <br /> (2 cm20 mm <br />0.02 m <br />) +
Syst. Nat. ed. +
minute +
darker +, tan +  and light-brown +
globular +  and ovoid +
campanulate +
1.2 cm12 mm <br />0.012 m <br /> (1.4 cm14 mm <br />0.014 m <br />) +
purple +  and green +
0.4 cm4 mm <br />0.004 m <br /> (?) +  and 1.2 cm12 mm <br />0.012 m <br /> (?) +
climbing +  and scrambling +
sprawling +, creeping +  and prostrate +
glabrate +  and glabrous +
25 cm250 mm <br />0.25 m <br /> (180 cm1,800 mm <br />1.8 m <br />) +
1.6 cm16 mm <br />0.016 m <br /> (3.4 cm34 mm <br />0.034 m <br />) +
Chelone obliqua +
species +
gibbous +  and not spurred +
1.4 cm14 mm <br />0.014 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +