大花黄牡丹

毛莨科芍药属落叶灌木。高1-2.5m，最高可达3.5m。叶为2回3出复叶，带有美丽的青铜色。花（2）3-4朵生枝顶或叶脉，直径8-12cm；花瓣、花丝与花药均为黄色；心皮1，少数2。花期5月，果期8-9月。 喜光，喜温暖，不耐瘠薄，畏炎热。西藏特有植物。仅产于米林、林芝（目前尚不能确定产于察隅、波密、隆子的类群是否为该种），生于海拔2900-3200m的雅鲁藏布江河谷及山坡林缘。它以植株高大、花朵硕大而显露、心皮数较少区别于滇牡丹P. delavaye，是极珍贵的牡丹观赏、育种材料。西藏林芝还产红蕊黄牡丹P.delavayi f. superba，与本种区别为植株矮小、花丝红色、心皮（3-5），不如大花黄牡丹常见。其原变型的模式标本采自云南，西藏可能有分布。

This is a deciduous shrub in the genus Paeonia (family Ranunculaceae). It grows 1–2.5 m tall, up to 3.5 m at maximum. Leaves are 2-ternately compound, with a distinctive bronze hue. Flowers (2) 3–4, borne at branch apices or leaf axils, 8–12 cm in diameter; petals, filaments and anthers are all yellow; carpels number 1, rarely 2. Flowering occurs in May, with fruiting in August–September. It prefers sunlight and warm climates, is intolerant of barren soils, and is susceptible to heat stress. Endemic to Tibet, it is only distributed in Mainling and Nyingchi (it remains unclear whether populations from Zayü, Bomi and Lhünzê belong to this species). It grows in Yarlung Zangbo River valleys and forest margins on mountain slopes at elevations of 2900–3200 m. This species differs from Paeonia delavayi by its taller stature, larger and more conspicuous flowers, and fewer carpels; it is an extremely valuable ornamental and breeding material for tree peonies. Nyingchi, Tibet also has Paeonia delavayi f. superba (red-stamen yellow peony), which differs from the present species by its shorter stature, red filaments, and (3–5) carpels; it is less common than the large-flowered yellow peony. The type specimen of its typical form was collected from Yunnan, and this taxon may also be distributed in Tibet.