SEED MORPHOLOGY IN OnobrychisMILLERSECTION HYMENOBRYCHIS DC. FROM TURKEY

ABSTRACT The seed (nutlet) morphology of four Onobrychis Miller (Fabaceae: subfamily Papilionoideae, Section Hymenobrychis DC.) taxa from Turkey, including three endemic taxa, was examined using scanning electron microscopy. Onobrychis tournefortii, O. galegifolia, O. cappadocica, O. albiflora. The seed examined exhibited variation in size, shape, colour, and surface sculpturing. Seed size ranged between 4.0-5.2 mm length and 2.0-3.6 mm width. Observed shapes included; ellipticus anguste asymmtricus reniformis, Ovatus anguste asymmetricus reniformis and ellipticus reniformis. Seed surface sculpturing revealed two distinct types: reticulate and rugulate. Species of Onobrychisare generally similar and confused with those of Hedysarumduring the identification process. Seed surface micromorphology can suggest taxonomical diagnostic characters for distinguishing species. Many of these characteristics are diagnostic at both the generic and specific levels.摘要 本研究利用扫描电子显微镜（scanning electron microscopy）对土耳其地区的4种驴食草属（Onobrychis Miller）类群（豆科Fabaceae：蝶形花亚科Papilionoideae，膜苞驴食草组Hymenobrychis DC.）的种子（小坚果）形态学特征进行了观察，其中包含3个特有类群，具体为驴食草（Onobrychis tournefortii）、山羊豆叶驴食草（O. galegifolia）、卡帕多奇亚驴食草（O. cappadocica）以及白花驴食草（O. albiflora）。所观察的种子在大小、形状、颜色及表面纹饰上均存在变异：种子长度范围为4.0~5.2毫米，宽度范围为2.0~3.6毫米；观察到的形状包括狭椭圆形不对称肾形（ellipticus anguste asymmetricus reniformis）、狭卵形不对称肾形（Ovatus anguste asymmetricus reniformis）与椭圆形肾形（ellipticus reniformis）。种子表面纹饰可分为两种清晰类型：网状（reticulate）与皱凸状（rugulate）。驴食草属（Onobrychis）物种在形态上普遍较为相似，物种鉴定过程中常与岩黄耆属（Hedysarum）物种相互混淆。种子表面微观形态可作为区分物种的分类学鉴定特征，其中多数特征在属级与种级分类阶元上均具备鉴定价值。