Centaurea solstitialis plant2 : 無料・フリー素材/写真
Centaurea solstitialis plant2 / Macleay Grass Man
| ライセンス | クリエイティブ・コモンズ 表示 2.1 |
|---|---|
| 説明 | Introduced, warm-season, annual or short lived perennial, erect herb, to 75 cm tall; taproot is about 20 cm long with numerous laterals. Leaves and stems are spineless and have a covering of downy hairs, giving a greyish appearance. Heads are solitary; bracts have stout spines and the florets are yellow and all tubular. Flowering is in spring and summer. Occurs in exposed situations on fertile or drier soils, usually in neglected areas and roadsides with poor ground cover. Occasionally invades unimproved grazing land; grows best in areas of more than 600 mm rainfall, but can be troublesome in semi-arid rangelands. Thought to be allelopathic, restricting growth of competing species. Poisonous to horses. Strong, competitive well managed pastures are the long term solution. Slashing can be an effective control; best undertaken at early flowering and in dry conditions; repeat slashing may be needed. Intensive grazing in spring before spines form will reduce seed set. Seedlings and rosettes can be controlled through repeated shallow cultivations. Herbicides are most effective when rosettes are small. |
| 撮影日 | 2014-01-23 11:43:04 |
| 撮影者 | Macleay Grass Man , Dungog, Australia |
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| 撮影地 | |
| カメラ | E5400 , NIKON |
| 露出 | 0.008 sec (1/126) |
| 開放F値 | f/7.1 |
| 焦点距離 | Asteraceae bractsspiny "Centaurea solstitialis" floretstubular floretsyellow flowerheadssolitary flowerheadsspherical introduced leaveslanceolate leaveslyrate leavespinnatifid plantsannual plantshairy plantsherb "St Barnabys Thistle" stemsbranched stemsgrey stemswinged weed |