Abstract

Transactions of seed coat of twelve species of Cassia L., namely C. alata L., C. angustifolia vahl., C. auriculata L., C. didymobotrya Fresen., C. glauca Lam., C. grandis Linn., C. hirsuta Linn., C. marylandica L., C. mimosoides DC., and C. pleuorocarpa F.Meull, C. siamea Lam., and C. spectabilis DC., were examined under scanning electron microscope. Variation in shape and size of the palisade and hourglass cells, occurrence of double layer of palisade cells in C. mimosoides, absence of endotestal hourglass cells in C. glauca, C. marylandica and C. mimosoides, appeared to be distinguishing characteristics for each species having taxonomic significance. The usefulness of these diagnostic characters of the testa depends on the levels of variation present among the different species of the same genus which may help in designing a key for identifying the taxa at specific level along with other characters of the seed.

中文摘要

以掃描式電子顯微鏡，觀察十二種Cassia L.植物 (即C. alata L., C. angustifolia vahl., C. auriculata L., C. didymobotrya Fresen., C. glauca Lam., C. grandis Linn., C. hirsuta Linn., C. marylandica L., C. mimosoides DC., and C. pleuorocarpa F.Meull, C. siamea Lam.,與C. spectabilis DC )的種皮橫切面，就其柵狀與沙漏狀細胞之形態與大小、C. mimosoides 具兩層柵狀細胞、C. glauca, C. marylandica, 及C. mimosoides不具內種皮之沙漏狀細胞等明顯特徵，顯示這些種皮的特徵具分類上的意義，而這些種皮鑑定特徵的應用，會因其變異在同屬不同種之間的層次而定，而此在確定特定分類階層時，有助於設計一個具有種子相關特徵的檢索表。

Keyword: Cassia, Anatomy, Seed coat, Palisade, Hourglass.