Taraxacum sect. Antarctica

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Taraxacum sect. Antarctica

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Systematics

Uhlemann & al. (2004), when recently revising Taraxacum sect. Antarctica stated: "The most important accounts of South American dandelions (Richards 1976, Dahlstedt 1907) recognize several (three to four) species within what is adopted as the section Antarctica in the present study, T. magellanicum, T. andinum, T. gilliesii and T. rhusiocarpum. Our species concept in Taraxacum does not principally differ from that of the above authors but there are substantial arguments in favour of the inclusion of all the populations of the South American Antarctica in a single taxon at the species level under the name T. gilliesii.

References


Dahlstedt H. 1907: Ueber einige südamerikanische Taraxaca. – Ark. Bot. 6(12): 1–19.

Richards A. J. 1976: An account of some neotropical Taraxacum species. – Rhodora 78: 682–706.

Uhlemann I., Kirschner J. & Štěpánek J. 2004: The genus Taraxacum in the southern hemisphere. I. The section Antarctica Handel-Mazzetti and notes on dandelions of Australasia. – Folia Geobot. 39: 205–220.

Description

Flowers and leaves develop simultaneously. Plants small, plant base subglabrous to slightly araneous. Middle leaves sparsely araneous or subglabrous. Leaf at hair base not swollen, leaf surface flat. Leaves undivided or shallowly lobate or deeply lobate but lobation uncomplicated and sparsely toothed, leaf lobes patent or pointing downwards, midrib without striatulate pattern, blade unspotted. Petioles unwinged to narrowly winged. Scapes unbranched, growing from the centre of leaf rosette, glabrous or subglabrous. Capitulum after flowering pointing upwards. Involucre with slightly subconical to rounded base. Flowers yellow. Florets usually ± numerous. Outer ligules flat. Pollen usually present, rarely absent. Stigma discoloured (usually pale green). Outer and inner involucral bracts flat, without corniculation or horns at the apex, rarely very slightly callose. Outer bracts 10–15 in well-developed plants, usually conspicuously imbricate or ± imbricate, adpressed or ± erect, lanceolate-ovate or ± ovate, ± short, almost glabrous, sparsely ciliate, or ciliate. Prevailing colour of exterior bracts: dark (dark green or black), borders distinct, usually medium broad to ± narrow, paler or reddish. Achenes straw brown, ochraceous or pale reddish or often blackish olivaceous to olivaceous, with numerous longitudinal ridges, often spinulose and tuberculate
throughout, achene body 3.5–4.5 mm long, medium thick, usually 0.9–1.0 mm wide, gradually, subabruptly, or ± abruptly narrowing into the cone. Cone conical (-subcylindrical), thick, 0.4 to 0.9 mm long. Rostrum thin, 5.0–8.0 mm long. Pappus 5.0–6.5 mm long, white or whitish-yellow, not deciduous. Receptacle glabrous. Plants sexual. Main flowering season: summer (under lowland conditions).

from: Uhlemann I., Kirschner J. & Štěpánek J. in Folia Geobot. 39: 209. 2004.

Distribution

Antarctic: Falkland Is. (Falkland Is.native) Australasia: Antipodean Is. (Antipodean Is.native); Chatham Is. (Chatham Is.native); New Zealand North (New Zealand Northnative); New Zealand South (New Zealand Southnative) Southern America: Argentina Northwest (La Riojanative, Mendozanative, San Juannative); Argentina South (Chubutnative, Neuquénnative, Rio Negronative, Santa Cruznative, Tierra del Fuego (Argentina)native); Chile Central (Santiagonative); Chile South (Los Lagosnative, Magellanesnative)