Taraxacum phymatocarpum J. Vahl s.s.
Asteraceae (Compositae), daisy family.
Fl. Dan. 13, 39: 6. 1840.
Type: Described from Greenland.
Sect. Arctica Dahlst: part of the Taraxacum phymatocarpum aggregate.
Vegetative morphology. Plants perennial herbs; 4–12(–30) cm high (CAN 273748); a slender, delicate, dwarf species with narrow, sub-entire or shallowly triangularly lobed deep green leaves and usually a single flower stalk; the flowering heads small, narrow and not expanding at anthesis; with milky juice. Taproot present. Caudex present. Vegetative, aerial, stem a small transition zone between roots and basal leaves. Leaves in a basal tuft, or basal in a rosette. Leaves patent (usually), or erect. Leaves alternate; simple; existing for a single season or less. Petioles present, or absent; 0–30 mm long; unwinged; glabrous. Leaf blade bases attenuate. Blades 15–35 mm long; 2.5–8(–13) mm wide (leaves to 13 mm, conspicuously wide, (CAN 500038)). Blades oblanceolate, or obovate; flat; veins pinnate. Blades adaxial surface glabrous. Blades abaxial surface glabrous. Blade margins lobed (shallowly, triangularly lobed), or not lobed. Blade margins entire (or sub-entire), or crenate, or dentate, or runcinate (in occasional robust plants; often variable on the same plant; bright green); glabrous; degree of incision 5–55 %. Leaf apices acute.
Reproductive morphology. Flowering stems present (often decumbent). Flowering stems without leaves; glabrous. Inflorescence a solitary head. Capitula 10–20 mm deep. Capitula 8–18 mm wide (remaining closed during anthesis; Porsild (1957)). Pedicels absent. Involucral bracts present; number of rows 2–3. Outer involucral bracts blade surface flat; mostly green (to bluish black and prunose); lying adjacent to the flowers, or spreading to erect; lanceolate (broadly), or ovate; glabrous; 3–5 mm high; 1.8–2.5 mm wide. Inner involucral bracts apex sometimes callose, but without a prominent horn; lanceolate (broadly); margins wide, scarious for at least one quarter of the bract, or at the most with narrow and scarious, less than one quarter of the bract (usually; rather variable); 12–14 mm high; 2.5–3 mm wide. With only ray florets. Flowers per inflorescence 35–50; zygomorphic. Calyx modified to a pappus. Calyx accrescent. Pappus with a single row of hairs. Pappus yellowish, or whitish. Ray floret pappus 4–6(–7) mm long. Petals fused; 5; yellow (a pale lemon yellow: sometimes drying with a pinkish tinge to the petals, but without the pink-grey stripe seen in T. hyparcticum); with contrasting markings (outer ligules with a grey, violet or purple stripe), or without contrasting markings (inner flowers). Corolla ligulate. Ray florets 35–50. Ray florets limb 8–9 mm long; 1–2 mm wide. Stamens 5. Anthers yellow; 3.5–4 mm long. Gynoecia inferior. Carpels syncarpous; 2. Styles 1. Stigmas per style 2; strap-like lobes. Placentation basal. Ovules 1. Fruit sessile. Fruit with calyx persisting; dry; cypselas; obovate; indehiscent. Fruit 3.3–4.5 mm long (cone about 1 mm long); 0.9–1.1 mm wide; black (or greyish); surface appearing veinless. Cypselas surface spinulose (usually over the entire surface); throughout (usually), or in upper half. Cypselas beak at least 3/4 of the length of the body; beak stout, not, or scarcely longer than the body. Seeds 1.
Chromosome information. 2n = 24. 2n = 24 (3x),
Mosquin and Hayley (1966 northern Canada), Johnson and Packer (1968 northwestern
Alaska), Zhukova (1968 north eastern Asia), Zhukova et al. (1973 north eastern
Asia), Petrovsky and Zhukova (1981 Wrangel Island), Tzvelev and Zhukova
(1986??), Zhukova and Petrovsky (1987a north and north eastern Asia);
32
(4x) & 40 (5x), Mosquin and Hayley (1966 northern Canada).
Ploidy levels recorded 3x&4x&5x.
Distribution. Common. Arctic Islands: Baffin, Devon, Ellesmere, Axel Heiberg, Parry Islands (Bathurst and Prince Patrick), Banks, Victoria, Prince of Wales, Somerset.
Ecology and habitat. Substrates: slopes, flood plains; dry, or moderately well drained areas; calcareous; rocks (talus), gravel (and stony areas), sand, clay (shale); with low organic content, or with high organic content. Habitats: silty, hummocky Jesse till (CAN 593650); gravel embankment; moist turfy places on rocky scree (CAN 223355); on owl perches (CAN 128188); raised low-centre polygons (CAN 526804); exposed muddy gravel (CAN 261600); dry alkaline clay flat (CAN 219932).
Notes. Leaves sub-entire to runcinate on the same plant. No horns on the bracts. Inflorescences relatively small and not spreading at anthesis. Achenes are black or grey and spinulose throughout, similar to the illustration in Dahlstedt (1905) page 25, see image library.
Illustrations. • Close-up of plant. Lemon yellow flowers with deeper colour on the tips of the petals and sub-entire leaves. Nunavut, Ellesmere Island, Tanquary Fiord. Lynn Gillespie 6469 and Laurie Consaul. CAN. • Close-up of plant. N.W.T. Banks Island, Aulavik Naitonal Park. on a ridgetop alongside the Thomsen River. UTM coordinates - 11X 415100 8105300. datum NAD27. Photographed by James McCormick, July 19, 2002. Note lemon yellow flowers and linear, almost entire leaves. • Side-view of flowers. Plant with entire to sub-entire leaves, involucral bracts that lack horns and lemon yellow petals. Note flowering heads erect, head going to seed has recureved towards the ground. Nunavut, Ellesmere Island, Tanquary Fiord. Lynn Gillespie 6469 and Laurie Consaul. CAN. • Close-up of plant. Lemon yellow flowers with deeper colour on the tips of the petals and sub-entire leaves. Nunavut, Ellesmere Island, Tanquary Fiord. Lynn Gillespie 6469 and Laurie Consaul. CAN. • Close-up of fruiting heads. Plant with bright red flowering scapes that were erect but have curved so that the flowering heads that are now maturing fruits have closed and are lying on the ground. Note involucral bracts without horns or callouses, and sub-entire leaves. Nunavut, Ellesmere Island, Tanquary Fiord 6469 and Laurie Consaul. CAN. • Black and white plate.. Illustration from the type description by Dahlstedt (1905). Note the entire to subentire or slightly runcinate leaves, the slightly modified tips to theinner involucral bracts and the fruit that is uniformly spinulose from the top to the bottom. • Arctic Island Distribution.
Cite this publication as: ‘S.G. Aiken, M.J. Dallwitz, L.L. Consaul, C.L. McJannet, L.J. Gillespie, R.L. Boles, G.W. Argus, J.M. Gillett, P.J. Scott, R. Elven, M.C. LeBlanc, A.K. Brysting and H. Solstad. 1999 onwards. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. Version: 29th April 2003. http://www.mun.ca/biology/delta/arcticf/’. Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993, 1995, 2000) should also be cited (see References).
