Highlander open

An annual herbaceous plant with thin open, upright or upright stems 15–20 (30) cm tall, strongly branched from the very base, covered with faint longitudinal stripes ^{[2] [3]} .

The leaves are bluish-green, simple, whole and whole-edged, elliptical, lanceolate or linearly oblong, 0.6-1.5 cm long and 2-6 mm wide, tapered wedge-shaped into a very short petiole, at the apex slightly dull or sharp , the lower ones are often opposite, with shortened internodes as if unclear, very rarely - all alternate. On the lower side, the middle vein is clearly visible and several lateral veins are clearly visible, on the upper side, the middle vein is usually noticeable quite well, and the lateral veins are almost not expressed, or all veins are hardly noticeable. The sockets at the base of the petioles are filmy, with 3-4 veins, brownish at the base, white above ^{[4] [5] [3]} .

Flowers are collected in the axils of the leaves (including at the first from the base of the branches) 2-5 (10), rarely solitary, crowded in the upper part of the stem. The perianth is filmy, yellowish or greenish, often whitish or pinkish along the edge, 1.5-2 mm long, its lobes are among five, oblong, divided into two-thirds of the length or stronger. When fruiting, the perianth does not fall, 2-2.5 mm long ^{[2] [4] [3]} .

Fruits are nuts 1.4–2.7 mm long, exceeding the perianth in length and protruding from it, narrow-ovate, trihedral, dark brown in color, somewhat shiny, densely covered with small dots, with a pointed top. The peduncle is elongated, sometimes exceeding the perianth in length ^{[4] [5] [3]} .

The chromosome set is 2n = 20 ^{[4] [6]} .

The area in Eurasia in the west is bounded by the north of the European part of Russia (the vicinity of Arkhangelsk, the Pechora basin), east - in the north of Western Siberia, in Eastern Siberia, in the Far East, in the south entering Mongolia and China ^{[3] [6]} .

Weed-field plant in the tundra, forest-tundra and northern taiga, apophyte . It clogs the crops of oats , perennial grasses, and various row crops ^[5] .

The species was first collected by Karl Merck in 1788 "between Lena and the Eastern Ocean" and transferred to Peter Simon Pallas under the name Polygonum humifusum , this sample is currently stored in the Pallas herbarium in Berlin. A valid description was published in 1849 by Karl Koch in Linnaea magazine:

P. humifusum Dr. Merk's coat of arms. Pallas. The plant is naked, branched from the base: branches sprawled to ascending; leaves are oblong, gradually narrowed into petiole, alternate and opposite; flowers are crowded, sessile and on very short pedicels, a bell covering the stem; nuts are smooth, shiny. Closest to P. herniarioides DC., From which it differs by more numerous flowers. Collected on Lena in Siberia by Dr. Merck, transferred to the herbarium in Berlin.

Original text (German)

P. humifusum Dr. Merk im Herb. Pallas. Glaberrimum, ex basi ramosum: ramis prostratis aut adscendentibus; Folia oblonga, in petiolum sensim attenuata, alterna et opposita; Flores aggregati, sessiles et brevissime pedunculati, ochrea brevi circumdati; Nuculae laeves, nitidae. Steht dem P. herniarioides DC. am Nächsten, unterschiedet sich aber durch die zahlreicheren Blüthen. Von dr Merk an der Lena in Sibirien gesammelt und dem Berliner Herbar mitgeheilt.

- Koch, K. Beiträge zu einer Flora der Orientes // Linnaea. - Halle ad S., 1849. - Vol. 22. - P. 205.

In 1850, K.F. Ledebur independently described this species under the same name after the sample transferred to the herbarium of Pallas Sievers from the vicinity of Tarbagatai .

Subspecies

Eric Hulten in 1968 suggested that the North American Polygonum caurianum may be closely related or identical to Polygonum humifusum . N. N. Tsvelev (1989) considered them synonyms, however, in 2003, morphological differences between them were shown, which made it possible to distinguish them as subspecies of one species.

• Polygonum humifusum C. Merck ex K. Koch subsp. humifusum - distributed mainly in Eastern Siberia and the Far East, in the west it enters the European part of Russia. Leaves and stems are green, perianth with straight lobes, occasionally reddish along the edge. A nutlet of 2.1 mm in length protruding from the perianth by 1 mm or more ^[7] .
• Polygonum humifusum subsp. caurianum ( BLRob. ) Costea & Tardif , 2003 - Distributed in northwestern Alaska , in the Yukon, and in the Northwest Territories . Described as a stand-alone species, modeled after the American pioneer Charles Leslie Mackay collected in Alaska in August 1882. Stems and leaves with a reddish tint (at least leaves along the edge), perianth with bent lobes, green or lilac, pink-lilac along the edge. The nutlet is up to 1.5-2.2 mm long, protrudes no more than 0.5 mm ^[7] .

Synonyms

Polygonum humifusum C. Merck ex K. Koch subsp. humifusum

• Polygonum humifusum Siev. ex Ledeb. , 1850 , nom. illeg.
• Polygonum humifusum f. yamatutae ( Kitag. ) CFFang , 1988
• Polygonum mandshuricum Skvortsov , 1943
• Polygonum yamatutae Kitag., 1964

Polygonum humifusum subsp. caurianum ( BLRob. ) Costea & Tardif , 2003

• Polygonum caurianum BLRob., 1904

• Tsvelev, N. N. Rod 15. Sporysh - Polygonum L. // Vascular plants of the Soviet Far East / ed. ed. S. S. Kharkevich . - L .: Nauka, 1989 .-- V. 4. - S. 116. - 380 p.
• Shlyakova, E.V. Genus Polygonum L. - Highlander // Key to weed-field plants of the Non-Chernozem zone. - L .: "Spike", 1982. - S. 71-76. - 208 p.
• Petrovsky, V.V. Genus 5. Polygonum - Highlander, buckwheat // Arctic flora of the USSR / ed. A.I. Tolmacheva . - M. - L .: Nauka, 1966. - T. V. - S. 168-169. - 208 p.
• Komarov, V. L. Rod 394. Highlander - Polygonum L. // Flora of the USSR : in 30 tons / chap. ed. V.L. Komarov . - M .; L .: Publishing House of the Academy of Sciences of the USSR , 1936. - T. 5 / ed. volumes V. L. Komarov. - S. 618-621. - 762, XXVI p. - 5175 copies.
• Li, AJ, Grabovskaya-Borodina, AE, Hong, SP, McNeill, J., Ohba, H., Park, CW 2. Polygonum Linnaeus // Flora of China. - 2003. - Vol. 5 .-- P. 285.
• Costea, M., Tardif, FJ Nomenclatural changes in the genus Polygonum section Polygonum (Polygonaceae) // Sida. - Vol. 20 (3). - P. 987-997.