eastern Joshua tree, Yucca jaegeriana : 無料・フリー素材/写真
eastern Joshua tree, Yucca jaegeriana / Jim Morefield
| ライセンス | クリエイティブ・コモンズ 表示-継承 2.1 |
|---|---|
| 説明 | eastern Joshua tree, Yucca jaegeriana, Nevada, Mormon Mesa, Virgin Valley drainage, elevation 620 m (2035 ft). Also visible are big galleta (Hilaria rigida), creosote bush (Larrea tridentata), bursage (Ambrosia dumosa), etc.Recently it has been recognized that there are two different species of Joshua tree in the Mojave Desert of the southwestern United States. The two species are distinguished mainly by flower shape, and are pollinated by different species of co-evolved yucca moths.The eastern Joshua tree shown here is limited to northwestern Arizona, southwestern Utah, southeastern Nevada, and the far eastern Mojave Desert portion of California. The more iconic western Joshua tree (Yucca brevifolia) is limited to southwestern Nevada and the western Mojave Desert in California, including Joshua Tree National Park. There is one area of overlap between the two species in Tikaboo Valley of south-central Nevada, northwest of the location shown here.Besides the flower differences, eastern Joshua tree tends to have shorter stems branched closer to the plant base (giving it a more shrubby appearance), shorter leaves not exceeding about 20 cm, and flowers longer than wide with segments curved outward at the tips. Western Joshua tree tends to be taller with a distinct trunk branching higher above the ground, with leaves up to 35 cm long, and flowers about as long as wide with segments curved inward. The leaf length, stem height, and branching characteristics are somewhat variable in both species and can't be used for definitive identification.For more information see Lenz, L.W. 2007. Reassessment of Yucca brevifolia and recognition of Y. jaegeriana as a distinct species. Aliso 24: 97-104. scholarship.claremont.edu/aliso/vol24/iss1/7 |
| 撮影日 | 2016-03-13 16:24:44 |
| 撮影者 | Jim Morefield , Nevada, USA |
| タグ | |
| 撮影地 | Nevada, United States 地図 |
| カメラ | E-510 , OLYMPUS IMAGING CORP. |
| 露出 | 0.001 sec (1/800) |
| 開放F値 | f/6.3 |
| 焦点距離 | 36 mm |