Arctanthemum arcticum

(Linnaeus) Tzvelev in A. I. Tolmatchew

in A. I. Tolmatchew, Fl. Arct. URSS 10: 115. 1987.

Illustrated
Basionym: Chrysanthemum arcticum Linnaeus Sp. Pl. 2: 889. 1753
Synonyms: Dendranthema arctica (Linnaeus) Tzvelev Leucanthemum arcticum (Linnaeus) de Candolle
Treatment appears in FNA Volume 19. Treatment on page 536.

Perennials, forming tufts of 1–10+ rosettes; rhizomes at or below-ground, fleshy, tough, branched; taproots (young plants) 3–6 (–10) mm diam. Stems glabrous or sparsely woolly proximally to ± densely white-woolly near heads. Leaves sometimes glaucous; petioles 0–95 mm; bases cuneate to truncate, sheathing to clasping (distal), margins revolute, teeth obtuse to rounded, sometimes mucronulate, faces glabrous or sparsely woolly, glabrescent; basal and proximal cauline blades ± fan-shaped to cuneate or spatulate, 6–50 × 4–35 mm, lobes usually 3–7, apices blunt; distal blades linear, 4–35 × 1–28 (–40) mm, bases attenuate, margins crenate, dentate, or entire, apices acute or obtuse; faces ± woolly, glabrescent. Peduncles usually bracteate, bracts 0–4, linear-lanceolate to linear, 6–19 mm. Ray laminae 8–12 mm. Disc corollas: tubes greenish yellow, (1.1–) 1.4–2 mm, throats and lobes yellow turning brownish, throats 0.7–1 mm, sometimes very sparsely glandular, lobes (0.25–) 0.4–0.6 mm. Cypselae 1.5–2.5 mm. 2n = 18 (72?).

Distribution

V19-932-distribution-map.gif

B.C., Man., N.W.T., Nunavut, Ont., Que., Yukon, Alaska, Coastal Alaska and low-arctic Canada, arctic Eurasia, ne Asia (s to Japan)

Discussion

Subspecies 2 (2 in the flora).

When Hultén described Chrysanthemum arcticum subsp. polare, he mapped the two subspecies. Along the Bering Strait in Alaska, all the material appears to belong to subsp. polare, except at Norton Bay, where a specimen (ALA) could be attributed to subsp. arcticum. That population would be very disjunct from the range of the subspecies along the south coast of Alaska. The two subspecies do not overlap widely in North America.

Selected References

None.

Key

1 Plants 10–40 cm (more in fruit); stems sometimes branched; blades of basal leaves fan-shaped to cuneate or spatulate, 3–5(–7)-lobed; ray laminae (15–)17–25(–31) mm, veins (5–)8–10(–12) Arctanthemum arcticum subsp. arcticum
1 Plants (2.5–)5–20(–26) cm (more in fruit); stems not branched; blades of basal leaves cuneate to spatulate, 0–3-lobed; ray laminae (7–)9–18(–21) mm, veins 4–5(–7) Arctanthemum arcticum subsp. polare
... more about "Arctanthemum arcticum"
not tailed +  and obtuse +
scarious +
spiciform +, racemiform +, paniculiform +  and corymbiform +
indeterminate +  and determinate +
Luc Brouillet +
(Linnaeus) Tzvelev in A. I. Tolmatchew +
0.6 cm6 mm <br />0.006 m <br /> (5 cm50 mm <br />0.05 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
glabrescent +
attenuate +
Chrysanthemum arcticum +
compound +  and simple +
lobed;spatulate;narrowly lanceolate +
linear-lanceolate +  and linear +
zygomorphic +, actinomorphic +  and (3-)5-merous +
yellow +  and white +
winged +  and monomorphic +
cylindro-obconic +
fertile +  and bisexual +
fertile +  and bisexual +
2.8 cm28 mm <br />0.028 m <br /> (4 cm40 mm <br />0.04 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (2.8 cm28 mm <br />0.028 m <br />) +
B.C. +, Man. +, N.W.T. +, Nunavut +, Ont. +, Que. +, Yukon +, Alaska +, Coastal Alaska and low-arctic Canada +, arctic Eurasia +  and ne Asia (s to Japan) +
sheathing +  and clasping +
gland-dotted +
glabrescent +, woolly +  and glabrous +
mucronulate;obtuse;rounded +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
in 2s +  and singly +
indeterminate +
heterogamous +  and homogamous +
each +  and sessile +
1.3 cm13 mm <br />0.013 m <br /> (2.9 cm29 mm <br />0.029 m <br />) +
patelliform;hemispheric +
elliptic to oblong or oblong-lanceolate +  and lance-elliptic +
sessile +  and petiolate +
cauline +  and basal +
0.025 cm0.25 mm <br />2.5e-4 m <br /> (0.04 cm0.4 mm <br />4.0e-4 m <br />) +
yellow turning brownish +
deltate +
sheathing +  and clasping +
entire +  and dentate +
woolly +  and glabrous +
crenate +, mucronulate +, obtuse +  and rounded +
2-carpellate +
persistent +
0 cm0 mm <br />0 m <br /> (9.5 cm95 mm <br />0.095 m <br />) +
25 +  and 34 +
in A. I. Tolmatchew, Fl. Arct. URSS +
0.8 cm8 mm <br />0.008 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
bearing subulate enations +, hairy +  and bristly +
dome--shaped +
below-ground +
5 +  and 8 +
exalbuminous +
Illustrated +
branched +  and simple +
appendaged +  and truncate +
papillate +
Dendranthema arctica +  and Leucanthemum arcticum +
0.3 cm3 mm <br />0.003 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
Arctanthemum arcticum +
Arctanthemum +
species +
yellow turning brownish +
campanulate +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
sheathing +  and clasping +
woolly +  and glabrous +
mucronulate +, obtuse +  and rounded +
0.11 cm1.1 mm <br />0.0011 m <br /> (0.14 cm1.4 mm <br />0.0014 m <br />) +
greenish yellow +
cylindric +
0.14 cm1.4 mm <br />0.0014 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
2.5 cm25 mm <br />0.025 m <br /> (5 cm50 mm <br />0.05 m <br />) +
5 cm50 mm <br />0.05 m <br /> (40 cm400 mm <br />0.4 m <br />) +
shrub +  and subshrub +