【目的】分析兰科植物营养器官结构对喀斯特生境的适应特性和不同兰科植物响应生境异质的生存策略，为兰科植物研究、保护与发展提供理论支持和参考依据。【方法】该研究以贵州北盘江喀斯特地区6种不同生活型兰科植物的叶、假鳞茎、根为研究对象。应用石蜡切片法，进行结构观察并测量相关指标，通过描述和方差分析、相关性分析和主成分分析。【结果】结果表明：(1)不同兰科植物结构特征间存在显著差异，丘北冬蕙兰、莎叶兰、兔耳兰和单叶石仙桃均为等面叶，叶片较薄；栗鳞贝母兰与梳帽卷瓣兰叶片为异面叶，有栅栏组织和海绵组织的分化，叶片较厚。(2)假鳞茎主要由表皮、基本组织和维管束组成，地生兰基本组织细胞较小，维管束密度大；附生兰基本组织细胞较大，储水结构较发达。(3)地生兰根被和皮层较厚，根被细胞排列紧密，皮层细胞小层数多；附生兰根被与皮层较薄，皮层细胞较大。(4)叶片下表皮厚度与叶片厚度、叶维管束直径、叶肉厚度、叶脉厚度呈极显著(?<0.01)正相关，叶肉厚度与下角质层厚度、茎维管束直径呈显著(?<0.05)负相关；茎直径和表皮厚度、茎维管束数量、茎横截面积呈极显著正相关，茎维管束直径占比与茎直径、表皮厚度、茎维管束数量、茎横截面积均呈极显著负相关；根的各指标间呈极显著正相关，根直径、根被厚度和皮层厚度与根维管束直径占比呈极显著负相关。【结论】兰科植物根部结构具有相对稳定的趋同适应性，叶片和假鳞茎结构间相互促进协调，是兰科植物响应干旱喀斯特环境的重要结构。 关键词 生态适应性；兰科植物；结构特征；喀斯特地区
【Objective】 The purposes of the study was to elucidate the adaptive traits of vegetative organ structure in Orchidaceae to Karst habitats, reveal the survival strategies of different orchid species in response to habitat heterogeneity, and provide theoretical support and reference for the research, protection and development of orchid species. 【Methods】 An investigation was conducted on the leaves, pseudobulbs, and roots of six Orchidaceae species with varying life forms in the Karst region of Beipan River, Guizhou Province. The paraffin section technique was employed to examine the structure and quantify relevant parameters. Descriptive and variance analyses, correlation analysis, and principal component analysis were employed for data analysis. 【Results】 The findings revealed that: (1) There were significant differences in structural characteristics among different orchid species. Cymbidium qiubeiense, Cymbidium cyperifolium, Cymbidium lancifolium and Pholidota leveilleana were isofacial leaves with thin leaves. The leaves of Coelogyne flaccida and Bulbophyllum andersonii were heterofacial, with palisade tissue and spongy tissue differentiation, and the leaves were thicker. (2) Pseudobulbs are mainly composed of epidermis, basic tissue and vascular bundle. The cells of basic tissue are small and the density of vascular bundle is large. The basic tissue cells of the pseudobulbs of epiphytic orchid are larger and the water storage structure is more developed. (3) The root coat and cortex of ground orchid are thick, the root coat cells are closely arranged, and the cortical cells are more small layers. The rhizome and cortex of epiphyte orchids are thin, and the cortical cells are large. (4) The thickness of the lower epidermis of leaves was significantly positively correlated with leaf thickness, leaf vascular bundle diameter, leaf flesh thickness, and leaf vein thickness (P < 0.01), while leaf flesh thickness was significantly negatively correlated with lower cuticle thickness and stem vascular bundle diameter (P < 0.05). Stem diameter was significantly positively correlated with epidermis thickness, stem vascular bundle number, and stem cross-sectional area, while stem vascular bundle diameter ratio was significantly negatively correlated with stem diameter, epidermis thickness, stem vascular bundle number, and stem cross-sectional area. The various indicators of roots were significantly positively correlated, and root diameter, root sheath thickness, and cortex thickness were significantly negatively correlated with root vascular bundle diameter ratio. 【Conclusion】 The research revealed that orchids possess a notably resilient convergent adaptability in comparable habitats, as evidenced by their stable root structure. Furthermore, the leaf and pseudobulb structures of orchids mutually facilitate and synchronize with one another, constituting the primary mechanism by which orchids respond to the arid karst environment.