Taraxacum holmenianum

Sahlin

Folia Geobot. Phytotax. 18: 445. 1983.

Common names: Holmen’s dandelion
Endemic
Basionym: Taraxacum pumilum Dahlstedt Ark. Bot. 4(8): 27, fig. 5. 1905,
Treatment appears in FNA Volume 19. Treatment on page 251. Mentioned on page 242, 244.

Plants 5–15 (–20) cm; taproots branched. Stems 1–7+, ascending, purple, glabrous or glabrate. Leaves ca. 10+, horizontal to widely patent, rarely ± erect, (dark green); petioles winged mostly narrowly; blades oblanceolate to oblong-oblanceolate (runcinate), (1.5–) 2–6 (–9) × 0.3–1.3 cm, bases attenuate, margins lobed regularly, ± alternately, shallowly to deeply, lobes usually straight to slightly retrorse, sometimes slightly antrorse, deltate to triangular, acute to acuminate, apices acute to acuminate, faces glabrous. Calyculi of 10–14, appressed to slightly spreading, purplish, ovate to lanceovate bractlets in 2 series, 3–6 (–7.5) × 1.8–2.5 (–3) mm, not or narrowly scarious, hyaline purplish, apices long-acuminate to short-caudate, tips scarious, erose. Involucres dark olive green, sometimes purplish, tips purplish, campanulate, 11–15 (–20) mm. Phyllaries ca. 14 in 2 series, lanceolate to lanceovate, 1–3 mm wide, margins not scarious or narrowly to widely scarious in proximal 1/2, sometimes distally, apices sometimes callous, sometimes also some small-horned, tips scarious, erose. Florets 30–50 (–60); corollas dark yellow (outer with distinct, central greenish gray or pinkish stripe, tips dark), 15–20 × 1–3 mm. Cypselae yellowish or straw-colored, bodies obovoid to oblanceoloid, 3.5–4.2 mm wide, cones narrowly conic, 0.9–1.1 mm, beaks slender, 4.5–5 mm, ribs 12–16 (3–4 prominent), sharp, faces proximally tuberculate, muricate in distal 1/2; pappi white to yellowish, 5.5–6.5 mm. 2n = 16.


Phenology: Flowering summer.
Habitat: Tundra hummocks and polygons, open slopes, on clay or gravel
Elevation: 0–300+ m

Distribution

V19-330-distribution-map.gif

Greenland, N.W.T., Nunavut.

Discussion

Taraxacum holmenianum is a strictly Arctic species. It is distinguished by its deep yellow ligules.

Selected References

None.

Lower Taxa

None.

"fine" is not a number.

... more about "Taraxacum holmenianum"
small-horned;long-acuminate;short-caudate +
ovate +  and lanceolate +
paniculiform +  and corymbiform +
indeterminate +  and determinate +
Luc Brouillet +
Sahlin +
attenuate +
Taraxacum pumilum +
slender +
0.45 cm4.5 mm <br />0.0045 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
compound +  and simple +
6 cm60 mm <br />0.06 m <br /> (9 cm90 mm <br />0.09 m <br />) +
2 cm20 mm <br />0.02 m <br /> (6 cm60 mm <br />0.06 m <br />) +
oblanceolate;oblong-oblanceolate +
0.3 cm3 mm <br />0.003 m <br /> (1.3 cm13 mm <br />0.013 m <br />) +
tuberculate +, rugose +, muricate +  and smooth +
obovoid;oblanceoloid +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.42 cm4.2 mm <br />0.0042 m <br />) +
0.6 cm6 mm <br />0.006 m <br /> (0.75 cm7.5 mm <br />0.0075 m <br />) +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
hyaline purplish +
0.3 cm3 mm <br />0.003 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
broadly ovate;lanceolate +
0.18 cm1.8 mm <br />0.0018 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
filiform +
white +  and cream-colored or yellowish +
Holmen’s dandelion +
0.09 cm0.9 mm <br />9.0e-4 m <br /> (0.11 cm1.1 mm <br />0.0011 m <br />) +
zygomorphic +, actinomorphic +  and (3-)5-merous +
1.5 cm15 mm <br />0.015 m <br /> (2 cm20 mm <br />0.02 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
straw-colored +  and yellowish +
tapered +, beaked +, flattened +, obcompressed +, compressed +, prismatic +, fusiform +, ellipsoid +, columnar +  and clavate +
Greenland +, N.W.T. +  and Nunavut. +
0–300+ m +
muricate +  and tuberculate +
winged +  and beaked +
dispersed +
Tundra hummocks and polygons, open slopes, on clay or gravel +
indeterminate +
each +  and sessile +
purplish +, green +  and dark olive +
0.8 cm8 mm <br />0.008 m <br /> (4 cm40 mm <br />0.04 m <br />) +
campanulate;cylindro-campanulate or urceolate +
sessile +  and petiolate +
erect +, horizontal +  and widely patent +
straight +
antrorse;retrorse +
deltate +  and triangular acute +
not scarious or +  and narrowly widely scarious +
2-carpellate +
white +  and yellowish +
persistent +
0.55 cm5.5 mm <br />0.0055 m <br /> (0.65 cm6.5 mm <br />0.0065 m <br />) +
Flowering summer. +
closing +  and later +
distinct +  and coherent +
subequal +  and unequal +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
Folia Geobot. Phytotax. +
bearing subulate enations +, hairy +  and bristly +
flat;convex +
12 +  and 16 +
exalbuminous +
1 (?) +  and 10 (?) +
glabrate +  and glabrous +
1 +  and 7 +
scapiform +
appendaged +  and truncate +
papillate +
Undefined tribe Lactuceae +
Taraxacum holmenianum +
Taraxacum +
species +
1.5 cm15 mm <br />0.015 m <br /> (2 cm20 mm <br />0.02 m <br />) +
campanulate +
1.1 cm11 mm <br />0.011 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
scarious +
with branched caudices +  and taprooted +
10 cm100 mm <br />0.1 m <br /> (30 cm300 mm <br />0.3 m <br />) +
30 cm300 mm <br />0.3 m <br /> (400 cm4,000 mm <br />4 m <br />) +
15 cm150 mm <br />0.15 m <br /> (20 cm200 mm <br />0.2 m <br />) +