內生真菌是生活在無症狀的植物組織內並不會引起顯著疾病的微生物。非內生真菌生長在植物表面並可能引起植物病。濱刺草是一個沿岸植物，具有穩定沙岸與保護沿岸地區的重要的功能，研究也表明濱刺草具有抗發炎之潛力，然而在研究上很少有與濱刺草有關之微生物的文獻發表。本研究中內生真菌之調查使用依賴培養法與不依賴培養法，在非內生真菌部分則使用傳統的伺機採集方法進行調查。經由依賴培養法與不依賴培養法，108個植物片段與600個克隆分別鑑定了19與12個內生菌。其中只有3個種類在這兩個方法被同時鑑定到，結果顯示結合兩種方法去鑑定植物之內生菌會比只使用一種方法來的更有效率。使用伺機採集方法，7個非內生真菌被鑑定，其中2種真菌也被發現與內生真菌相同。在本研究中利用了以上三種方法並依據RNA polymerase II second largest subunit DNA 序列與型態學之特徵，同時也發現了Neostagonospora 屬的一個世界新種，Neostagonospora spinificis。產孢細胞之形狀與分生孢子橫隔數目、大小都是有用的特徵來區分Neostagonospora 屬之不同種。;Endophytic fungi are microorganisms that live asymptomatically within plant tissues without causing apparent disease. Non-endophytic fungi grow on the plant surface, some of them may cause disease. Spinifex littoreus is an important coastal grass for stabilizing and protecting sand coastal areas and it has been shown to have anti-inflammatory properties, however, few has been published about the organisms associated with this plant. In this study, endophytic fungi were investigated by culture-dependent and culture-independent approaches and non-endophytic fungi were investigated by the opportunistic collection approach. By the culture-dependent and culture-independent approaches, 108 plant segments and 600 colonies yielded 19 and 12 species of endophytic fungi, respectively. Only 3 species were identical in both approaches, indicating that the combination of two approaches to detect endophytic fungi is more effective than a single approach. By the opportunistic collection approach, 7 species of non-endophytic fungi were identified; two of them were conspecific with endophytes. In this study, a new species of Neostagonospora was found by these approaches according to characterization by RNA polymerase II second largest subunit (RPB2) DNA sequences and micromorphology. The shape of conidiogenous cells as well as numbers of septa and size of conidia are useful characters for distinguishing between species of Neostagonospora.