Soft honeygrass

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Soft honeygrass
Soft honeygrass (Holcus mollis)

Soft honeygrass ( Holcus mollis )

Systematics
Commelinids
Order : Sweet grass (Poales)
Family : Sweet grasses (Poaceae)
Subfamily : Pooideae
Genre : Honey grasses ( holcus )
Type : Soft honeygrass
Scientific name
Holcus mollis
L.

The soft honeygrass ( Holcus mollis ) is a plant species within the sweet grass family (Poaceae). It is widespread in Europe .

Regional trivial names are also known as bog mercury, instep grass or seed grass.

description

Illustration from Flora Batava , Volume 7.

Appearance and leaf

The soft honeygrass is an evergreen , perennial herbaceous plant that reaches heights of between 20 and 100 centimeters. It forms loose lawns or dense clumps with upright or spreading stalks . The above-ground parts of the plant are only sparsely and briefly hairy. The lower part of the stem base is veined reddish-brownish on a brownish background. The bald to sparsely hairy stalks are thin and have four to seven knots with a thick beard of hair.

The leaves are divided into leaf sheath and leaf blade. The leaf sheaths on the back are rounded, glabrous or not very hairy, then with hairs turned back. The ligules are membranous, serrate, blunt and about 1 to 5 millimeters long. The leaf blades are pointed, reach 4 to 20 centimeters in length and up to 12 millimeters in width. They are flat, gray-green, very short-haired or bald and feel slightly rough.

Inflorescence and flower

The whitish, pale gray or purple colored, paniculate overall inflorescences are narrow-oval or egg-shaped, very dense to loose and 4 to 12 centimeters long. The panicle branches are hairy. The elongated to elliptical, 4 to 6 millimeters long spikelets fall closed when ripe. The spikelets are usually two-, rarely three-flowered, the lower flower is hermaphrodite, the upper one usually male. The paper-like glumes are about as long as the spikelet and are hairy short and stiff on the keels and nerves. The lower one is narrow-lanceolate and single-nerved; the upper egg-shaped to elliptical, three-nerved. The lemmas are between 2.5 and 3 millimeters long and are completely enclosed by the glumes. They are indistinctly five-nerved and have a beard of hair at the base. They are smooth or finely haired on top and shiny. The lower one is dull and unfurled; the upper one is branded on the back near the tip. This awn is between 3.5 and 5 millimeters long and is only slightly curved and protrudes from the glumes. The flowering period is between June and August.

The number of chromosomes is 2n = 14, 28, 35, 42 or 49.

Possible confusion

The overall stronger (woolly hairy) woolly honeygrass ( Holcus lanatus ) is very similar . However, this grass does not have long, tough rhizomes and the stalk nodes are downy, not bearded hairy. It also has hook-shaped awns on the upper lemmas that do not protrude from the glumes.

ecology

The soft honey grass is a rhizome - Geophyt , a root-buds Geophyt and a Hemikryptophyt forms, the loose turf. It is an acid, sand and leanness indicator and a soil stabilizer.

In Central Europe there is hardly any fruit, instead there is an abundant vegetative reproduction by the rhizomes. Even small pieces of rhizome can grow into new plants. At a depth of 15 to 20 cm, about 40 meters of rhizomes were found on 1 square meter of sandy soil.

Agriculturally, it is considered a " weed ", especially on sandy fields, as it spreads over long creeping rhizomes and new plants can develop from each rhizome fragment.

Occurrence

The soft honeygrass is common throughout Europe and Northwest Africa. It is significantly less common than the similar woolly honeygrass ( Holcus lanatus ). It is a neophyte in North America .

It is also scattered everywhere in Germany and in some areas it is frequent from the lowlands to altitudes of around 1500 meters. In the Allgäu Alps in Bavaria, southwest of the Weiherkopf , it rises up to 1520 meters above sea level.

It grows on almost all soils from heavy loams to sand . It prefers to colonize moderately fresh to dry, base and nutrient poor, strongly acidic, musty-peaty, humus-rich, sandy-stony soils. It is an acid pointer as well as a penumbra plant. Its main distribution area is in open forests and forest edges, mainly in shady locations, in shrubbery heather and hedges , occasionally also in poor grassland and raised bog grassland. It also populates fields or plowed meadows. It cannot survive in cultivated areas with a good supply of nutrients and a favorable calcium balance. Even with intensive grazing, the grass decreases significantly.

It is considered an association character type of the oak and birch forests, Quercion-robori-petraeae. In some areas it is a character species of the Holco-Quercetum, but also occurs in societies of the Pruno-Rubion, Epilobion angustifolii or the Nardo-Callunetea class.

photos

literature

  • E. Oberdorfer: Plant-sociological excursion flora. Ulmer, Stuttgart 1994. ISBN 3-8252-1828-7 . Erich Oberdorfer : Plant-sociological excursion flora . With the collaboration of Theo Müller. 7th, revised and expanded edition. Eugen Ulmer, Stuttgart (Hohenheim) 1994, ISBN 3-8252-1828-7 .
  • Henning Haeupler , Thomas Muer: picture atlas of the fern and flowering plants of Germany (= the fern and flowering plants of Germany. Volume 2). Published by the Federal Agency for Nature Conservation. Ulmer, Stuttgart 2000, ISBN 3-8001-3364-4 .
  • CE Hubbard: Grasses - Description, Distribution, Uses. Ulmer Verlag, Stuttgart, 1985. ISBN 3-8001-2537-4 .
  • E. Klapp & WO v. Boberfeld: Pocket book of grasses. Recognition, determination, location and socialization, evaluation and use. Paul Parey Publishing House, Berlin, Hamburg, 1990. ISBN 3-489-72710-X

Individual evidence

  1. a b Erich Oberdorfer : Plant-sociological excursion flora for Germany and neighboring areas . 8th edition. Verlag Eugen Ulmer, Stuttgart 2001, ISBN 3-8001-3131-5 . Page 243.
  2. a b c Ruprecht Düll , Herfried Kutzelnigg : Pocket dictionary of plants in Germany and neighboring countries. The most common Central European species in portrait . 7th, corrected and enlarged edition. Quelle & Meyer, Wiebelsheim 2011, ISBN 978-3-494-01424-1 .
  3. Erhard Dörr, Wolfgang Lippert : Flora of the Allgäu and its surroundings. Volume 1, IHW, Eching 2001, ISBN 3-930167-50-6 , p. 165.

Web links

Commons : Soft honeydew  album with pictures, videos and audio files