1. Spirodela. CYPERACEAE. 99 



9. C. pseudocyperus, L. Stems triquetrous, 50 cm. to lm. high, scabrous on margins ; 

 leaves flat ; spikelets 3-6, pedunculate, drooping, 3-6 cm. long, all near together towards 

 the top of the stem, the uppermost male, the others female ; floral bracts leafy, much 

 exceeding the inflorescence ; glumes pointed ; utricle spreading, narrow, shortly stalked, 

 strongly nerved, tapering into a long 2 -cleft beak. 



Mount Lofty Range ; Kangaroo Island ; River Murray ; South-East. Summer. 



Family 22.— LEMNACEAE. 



Flowers very rare, unisexual, the males consisting of 1 stamen and the females of 1 

 carpel, growing on the leaf and sometimes contained in a minute spathe ; fruit a small 

 utricle. Small floating plants, free in the water, each consisting of a leaflike lamina or 

 shoot (here called "leaf") and propagating themselves by similar lateral growths from the 

 edges of the leaves. Duckweed). 



The disk-like laminas are considered by some botanists to be modified stems, by others 

 to be true leaves. 



A. Leaves with roots growing from the undersurface. 



Roots 2 or more to each leaf Spirodela 1. 



Root 1 to each leaf Lemna 2. 



A. Leaves without roots Wolffta 3. 



1. SPIRODELA, Schleiden. 



1. S. oligorrhiza (Kurz), Hegelm. Leaves ovate, thin, 3-4 mm. long, with several 

 lateral converging nerves, and each leaf with 2-5 roots from the lower surface ; flowers 

 issuing from a slit in the edge of the leaf 1 female and 2 males within a minute spathe. — 

 Lemna oligorrhiza, Kurz. 

 Reedbeds, near Adelaide. 



2. LEMNA, L. 

 (Greek name of a water-plant.) 

 Flowers as in Spirodela, but only 1 root to each leaf, and the nerves inconspicuous or 

 none. 



A. Leaves lanceolate or oblong L. trisulca 1. 



A. Leaves ovate or suborbicular. 



Leaves flat L. minor 2. 



Leaves convex below L. gibba 3. 



1. L. trisulca L. Leaves oblong or lanceolate, thin, petiolate, 10-12 mm. long with 

 the petiole ; 3 or more united together, often dichotomously. 



River Murray ; South-East. 



2. L. minor, L. Leaves broadly ovate, opaque, flat, 2-4 mm. long, separating when 

 mature. 



In still water in southern districts. 



3. L. gibba, L. Leaves obovate, flatfish above, convex and spongy below. 

 Mount Gambier. 



3. WOLFFIA, Hork. et Schleid. 

 (After J. F. Wolff, German physician and botanist, 1778-1806.) 

 1. W. arrhiza (L.), Wimm. Very small floating plant ; leaf about 1 mm. diam., thick, 

 very convex beneath, without roots ; flowers rising on the surface of the leaf, without a 

 spathe ; stamen solitary with an almost sessile anther. 

 River Murray. 



Family 23.— RESTIONACEAE. 



Flowers unisexual and mostly dioecious, or rarely bisexual, arranged in spikelets or 

 panicles, each flower in the axil of a rigid glume ; perianth of 6 or fewer glume-like seg- 

 ments, rarely none ; male flowers of 3 stamens ; anthers 1 -celled ; female flowers with a 

 1-3-celled ovary, and 1-3 slender styles or branches ; ovule 1 in each cell, pendulous ; 

 fruit a capsule or nut ; seed albuminous. Rush-like perennials, the leaves almost reduced 

 to brown distichous sheathing bracts imbricate at the base of and distant along the stem, 

 split on one side and not tubular, as in Cyperaceae. 



A. Ovary 3-celled ; flowers panicled Lepyrodia 1. 



A. Ovary 1 -celled. 



B. Styles or style -branches 3. 



Female spikelets several-flowered Leptocarptjs 2. 



Female spikelets 1 -flowered Hypolaena 3. 



B. Style undivided. 



Female spikelets 1 -flowered Loxocarya 4. 



Female spikelets several-flowered Lepidobolus 5. 



