封面植物介绍——塔黄

Introduction of the Plant Front Cover:Rheum nobile

塔黄(Rheum nobile J. D. Hooker et Thomson),又名高山大黄,隶属于蓼科大黄属。多年生高大草本。根及根状茎粗壮,可入药。茎单生,挺直,高1~2 m, 具多数基生叶、茎生叶和叶状苞片。基生叶数片呈莲座状,圆形或近心形,直径20~30 cm。茎生叶及叶状苞片向上渐小,近圆形,直径5~13 cm。叶状苞片淡黄色,交互覆盖,形成了一个不透风、半透明的塔状温室,以抵御高海拔低温、强风和强紫外线.

Rheum nobile J.D.Hooker et Thomson,also named Gaoshan Da Huang,belongs to a member of the genus Rheum from the family Polygonaceae.The plants are perennial herbs,having stout roots and rhizomes which can be used as medicine.The stems are simple,erect,1-2 m tall,with numerous basal leaves,stem leaves and leaf-like bractes.The basal leaves are rosulate,orbicular,ovate,or cordate-ovate,20-30 cm in diam.The stem leaves and leaflike bracts are smaller upward,suborbicular,5-13 cm in diam.The bracts are yellowish,covered with each other to form an airtight and translucent tower shaped greenhouse to resist high altitude,low temperature,strong wind and strong ultraviolet rays,and protect the axillary inflorescences inside the bracts.Rheum nobile needs as much as 15-45 years of vegetative growth to accumulates enough nutrients until it matures.It blossoms once a lifetime,then the plant dies as the fruit matures with the final nutrients distributed to the seeds.Flowering from June to July;fruiting in September.