Murdannia Royle, Bot. Himal. 403. tab. 95. fig. 3. 1839; Brückner in Engler, Naturlich. Pflanzenfam., ed. 2, 15a: 173. 1930; Brenan, Kew Bull. 179. 1952; Morton, J. Linn. Soc. Bot. 60: 202. 1967; Rao et al., J. Linn. Soc. Bot. 60: 367-369. 1968; D. Y. Hong, Acta Phytotax. Sin. 12 (4): 467, 1974; K. C. Hs.
水竹葉屬
Aneilema R. Br. Prodr. 27. 1810.
Annual or perennial herbs, some with stolons. Roots fibrous, sometimes thickened, or with fusiform tubers. Stems usually dimorphic: the vegetative shoot acaulescent; erect; the flowering shoots one to several per plant, ascending or decumbent. Leaves linear, lanceolate, or oblanceolate, cartilagineus, sometimes conduplicatus. Prophyll sheathing, apex bifid. Inflorescences terminal, a single cincinnus or a thyrses or sometimes flowers solitary; bracteolates fugacious, marcescent or persistent. Flowers usually dimorphic: in functionally male flowers the style central and straight, the pistil vestigial, stamens symmetrically arranged; in bisexual flowers the style curved to one side and the stamens to the opposite side; sepals free, lanceolate, boat-shaped, equal, apex obtuse; petals suborbicular, purple, fertile stamens 2-3, antesepalous, anthers purple to black, narrowly elliptic-oblong; pollen whitish, filaments bearded, the hairs moniliform; staminodes 3-4, usually unequal, when 4, one antesepalous, the anther vestigial, the filament bearded; the others antepetalous, equal, antherodes trilobed, yellow, filaments bearded or glabrous; ovary ellipsoid in outline, acutely 3-angled; style thickened toward the base. Capsule trilocular, 3-valved, ellipsoid, 3-angled, apex mucronulate. Seed brown, deltoid in outline, dorsiventral, embryotega semilateral or dorsal, hilum linear or punctiform.
Species ca. 50, distributed in tropics and subtropics, mainly in Asia; nine species and one variety in Taiwan .
Brücker (1930) 首先依據花被的對稱性，將Murdannia自Aneilema分出；Woodson (1942) 則認為Aneilema花部形態是對稱的，子房及果實皆為3室，主張應該合併；Brenan (1952) 強調退化雄蕊的形態及排列方式，贊同Brucker (1930) 的處理；之後，許多細胞學的報導 (Kammathy & Rao, 1961b, 1964; Jones & Jopling, 1972)、解剖學上的證據 (Tomlinson, 1966) 及花粉形態的觀察 (Pool & Hunt, 1980)都支持這樣的處理，因此，將Murdannia獨立為一屬，應為合理的處理。
本屬植物之花絲上著生多細胞毛，細胞為四方形及圓形，表面密布瘤狀突起，排列成念珠狀 (圖5B )；Amischotolype，Belosynapsis及Cyanotis屬花絲上也著生念珠狀的毛，但細胞為卵形 (圖5A)，不同於本屬植物；另外，本屬植物前出葉 (prophyll) 先端為銳尖的二個突起，省產其他屬的植物前出葉先端僅微突，因此前出葉特徵為鑑定本屬的良好特徵。
本屬植物之營養器官十分類似，而許多花部的特徵在製成標本後都無法觀察，使得種間鑑定困難。本研究經過詳細形態觀察後，發現綜合植株生長形態、根粗細、葉子寬度、花序類型、花部特徵、種子形態等，可以清楚劃分出種的界限。
