font settings and languages

Font Size: Large | Normal | Small
Font Face: Verdana | Geneva | Georgia
Languages:

Arrhenatherum elatius bulbosum 'Variegatum'

(Bulbous Oat Grass)

Common Names

[ Back to top ]

Common Names in English:

Bulbous Oat Grass

Description

[ Back to top ]

Family Poaceae

Annual or perennial herbs, or tall woody bamboos . Flowering stems (culms ) jointed , internodes hollow or solid; branches arising singly from nodes and subtended by a leaf sheath and 2-keeled prophyll, often fascicled in bamboos. Leaves arranged alternately in 2 ranks , differentiated into sheath, blade , and an adaxial erect appendage at sheath/blade junction (ligule) ; leaf sheath surrounding and supporting culm-internode, split to base or infrequently tubular with partially or completely fused margins , modified with reduced blade in bamboos (culm sheaths) ; leaf blades divergent, usually long, narrow and flat, but varying from inrolled and filiform to ovate , veins parallel, sometimes with cross-connecting veinlets (especially in bamboos) ; ligule membranous or a line of hairs . Inflorescence terminal or axillary , an open, contracted , or spikelike panicle, or composed of lax to spikelike racemes arranged along an elongate central axis, or digitate, paired , or occasionally solitary; axillary inflorescences often many, subtended by spatheoles (specialized bladeless leaf sheaths) and gathered into a leafy compound panicle; spikelets often aggregated into complex clusters in bamboos. Spikelets composed of distichous bracts arranged along a slender axis (rachilla) ; typically 2 lowest bracts (glumes ) empty, subtending 1 to many florets ; glumes often poorly differentiated from accompanying bracts in bamboos. Florets composed of 2 opposing bracts enclosing a single small flower, outer bract (lemma) clasping the more delicate, usually 2-keeled inner bract (palea) ; base of floret often with thickened prolongation articulated with rachilla (callus) ; lemma often with apical or dorsal bristle (awn ), glumes also sometimes awned . Flowers bisexual or unisexual ; lodicules (small scales representing perianth) 2, rarely 3 or absent, 3 to many in bamboos, hyaline or fleshy ; stamens 3 rarely 1, 2, 6, or more in some bamboos, hypogynous, filaments capillary , anthers versatile; ovary 1-celled, styles (1 or) 2(rarely 3), free or united at base, topped by feathery stigmas, exserted from sides or apex of floret. Fruit normally a dry indehiscent caryopsis with thin pericarp firmly adherent to seed, pericarp rarely free, fleshy in some bamboos; embryo small or large; hilum punctate to linear .

About 700 genera and 11,000 species: widely distributed in all regions of the world.[1]

Genus Arrhenatherum

Perennial . Culms tall, basal internodes often swollen into globose corms. Leaf blades linear , flat. Inflorescence a moderately dense panicle. Spikelets weakly laterally compressed , florets 2, dimorphic , sometimes with an additional rudiment , lower floret staminate and strongly awned , upper floret bisexual and weakly awned or awnless; rachilla disarticulating above glumes but not between florets, extended beyond terminal floret; glumes unequal, thin, lower glume 1/2 spikelet length or more, 1-veined, upper glume as long as spikelet, 3-veined; lemmas firmly membranous to subleathery, rounded on back, 5-9-veined, apex 2-denticulate; lower lemma awned from near base , awn geniculate with twisted column, exserted from spikelet; upper lemma with a short straight awn or awnless; palea slightly shorter than lemma, keels ciliate . Ovary apex hairy ; hilum linear.

Seven species: SW Asia, Europe, Mediterranean region; one species (introduced ) in China.[2]

Physical Description

Habit: Clumping

Foliage: Grass , striped white • Foliage Shape: Linear • Normal foliage color: Green • Underside foliage: Green • Juvenile foliage: Green • Mature foliage: Green • New foliage: Green • Spring foliage: Green • Summer foliage: Green • Fall foliage: Green • Winter foliage: Green

Size/Age/Growth

Growth Rate: Slow Growing • Size: 24-36" tall.

Landscaping

Care: Follow a regular watering schedule during the first growing season to establish a deep, extensive root system. For a neat appearance , remove old foliage before new leaves emerge . Divide clumps every 2 to 3 years in early spring .

Habitat

Biome: Disturbed areas, urban areas

Biology

[ Back to top ]

Growth

Culture: Space 12-15" apart.

Sunlight: Sun Exposure: Partial to Full Shade.

Moisture: Drought Tolerance: High • Water Requirements: Water regularly, when top 3 in. of soil is dry.

Temperature: Heat Zones: High: 8 (>90 to 120 days) Low:1 (< 1 days) (map) • Cold Hardiness: 3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b, 10a, 10b. (map)

Taxonomy

[ Back to top ]

Similar Species

[ Back to top ]

Members of the genus Arrhenatherum

There are approximately 78 species in this genus:

A. alatius · A. album · A. album var. erianthum · A. almijarense · A. americanum · A. asperum · A. avenaceum · A. avenaceum var. bulbosum · A. avenaceum var. nodosum · A. baeticum · A. barbatum · A. biaristatum · A. bispanicum · A. bromoides · A. bulbosum · A. calderae · A. capense · A. cechicum · A. compactum · A. delavayi · A. desertorum · A. dodii · A. elatior · A. elatius (False Oat Grass) · A. elatius bulbosum var. bulbosum (Tuber Oat Grass) · A. elatius bulbosum 'Variegatum' (Bulbous Oat Grass) · A. elatius sardoum · A. elatius subsp. baeticum · A. elatius subsp. braun-blanquetii · A. elatius subsp. sardoum · A. elatius tuberosum · A. elatius var. bulbosum (Tuber Oatgrass) · A. elatius var. bulbosum 'Variegatum' · A. elatius var. elatius (Tall Oatgrass) · A. elatius var. nodosum · A. elongatum · A. erianthum · A. exserens · A. filifolium · A. galpinii · A. hirtulum · A. hookeri · A. ilievii · A. junghuhnii · A. kotschyi · A. kotschyii · A. lachnanthum · A. leoninum · A. longifolium · A. longum · A. macrostachyum · A. mannii · A. milanjianum · A. montanum · A. mortonianum · A. murcicum · A. natalense · A. nebrodense · A. palaestinum · A. palestinum · A. pallens · A. parlatorei · A. pratense · A. precatorium · A. pubescens · A. puelii · A. riofrioi · A. rivulare · A. rupestre · A. sardoum · A. sedenense · A. setaceum · A. sulcatum · A. thorei · A. tuberosum · A. umbrosum · A. variegatum · A. virescens

More Info

[ Back to top ]

Further Reading

[ Back to top ]

Notes

[ Back to top ]

Contributors

Identifiers

Footnotes

  1. Shou-liang Chen, De-Zhu Li, Guanghua Zhu, Zhenlan Wu, Sheng-lian Lu, Liang Liu, Zheng-ping Wang, Bi-xing Sun, Zheng-de Zhu, Nianhe Xia, Liang-zhi Jia, Zhenhua Guo, Wenli Chen, Xiang Chen, Yang Guangyao, Sylvia M. Phillips, Chris Stapleton, Robert J. Soreng, Susan G. Aiken, Nikolai N. Tzvelev, Paul M. Peterson, Stephen A. Renvoize, Marina V. Olonova & Klaus Ammann "Poaceae". in Flora of China Vol. 22. Published by Science Press (Beijing) and Missouri Botanical Garden Press. Online at EFloras.org. [back]
  2. Zhen-lan Wu & Sylvia M. Phillips "Arrhenatherum". in Flora of China Vol. 22 Page 6, 316, 322. Published by Science Press (Beijing) and Missouri Botanical Garden Press. Online at EFloras.org. [back]
Last Revised: 2009-04-29