48 POTAMOGETONACEAE. 6. Buppia. 



3. P. acutifolius, Link. Resembles the preceding, but the leaves are acute, with 

 numerous fine longitudinal nerves, and the fruits have a small tooth at the base of the 

 inner margin. 



Recorded for the River Murray in Victoria, and probably to be found in our State, 

 but I have not seen a specimen. 



4. P. pectinatus, L. Stems very slender, dichotomous ; leaves narrow-linear, dilated 

 into a long sheathing base, with 2 lanceolate lobes (stipules) ; fruits rather large (3-4 mm. 

 long), obovoid, with a very short, almost lateral beak. 



Creeks and freshwater swamps. Sept. -Dec. 



5. P. Tepperi, A. Benn. Upper leaves on long petioles, the lamina floating, ovate or 

 orbicular, sometimes cordate at base, thick, with 19-25 nerves ; spike dense cylindrical ; 

 fruits obovoid, rounded on back and with 3 almost smooth ribs ; beak very short. — 

 P. natans, R. Br. partly, not of L, 



Rivers and swamps of southern and south-eastern districts. Nov. -Jan. 



6. P. tricarinatus, A. Benn. Near the preceding, but the leaves are ovate-oblong 

 with 13-17 nerves ; fruits with the 3 dorsal ribs strongly crenulate or tuberculate. — 

 P. natans, R. Br. partly, not of L. 



Murray River and in creeks and swamps. Nov. -Jan. 



6. RUPPIA, L. 

 (After H. B. Ruppius, a German botanist ; lived 1689-1719.) 

 1. R. maritima, L. Submerged plant inhabiting brackish water ; leaves long, filiform, 

 clustered, with sheathing bases which shelter the young spike ; flowers bisexual, naked, 

 2, on opposite faces of the axis of the spike ; anthers 2, sessile, 2-celled, pollen globular ; 

 carpels 4-8, with 1 pendulous ovule and peltate stigma ; carpels at first sessile, but 

 becoming pedicellate as they ripen and raised to the surface of the water on a long spirally 

 coiled peduncle. 



Brackish waters near the sea. Oct. -Dec. 



Family 15.— NAJADACEAE. 



Differs from Potamogetonaceae chiefly in the erect ovule, the toothed leaves, and the 

 perianth represented by a membranous cup-shaped bract ; flowers unisexual, solitary 

 in the axils of the opposite or whorled leaves ; carpel 1. 



1. NAJAS, L. 



(Greek naias, a naiad or water-nymph.) 



Flowers dioecious, solitary, axillary ; male flower of 1 anther, with 1 or 4 cells, enclosed 



in a membranous bract or perianth ; pollen globular ; female flower of 1 sessile carpel 



with a 2-3-branched style and 1 small bract. Submerged waterplants ; leaves opposite 



and often appearing whorled. 



Leaves prominently toothed N. major 1. 



Leaves with minute teeth N. tenuifolia 2. 



1. N. major, All. Leaves linear, 2-3 mm. broad, sinuately and prominently toothed, 

 the sheathing base not lobed ; anther 4-celled ; style 2-3-branched. 



River Murray. A cosmopolitan species. Jan. -Mar. 



2, N. tenuifolia, R. Br. Leaves narrow-linear, 1 mm. broad, with small distant teeth 

 scarcely visible except under the lens, the sheathing base produced into 2 stipular lobes 

 toothed like the leaf -blade ; style 2 -branched. 



Recorded from the MacDonnell Ranges and probably occurs in our Far North. Jan.- 

 Mar. 



Family 16— APONOGETONACEAE. 



Flowers bisexual, arranged in spikes ; perianth of 2 petal-like segments ; stamens 

 6-18, in 2 or 3 whorls ; carpels 3-6, each with 2-6 erect ovules. Freshwater plants. 



1. APONOGETON, Thunb. 

 (From Aponus, the Latin name of the town of Albano, and Greek geiton, near.) 



* I. A. distachyus, Thunb. Cape Pondweed. Rootstock bulbous ; leaves floating, 

 large, oblong, with long, sheathing petioles ; flowers sessile, scented, in terminal forked 

 spikes ; the 2 perianth -segments broad, opposite, white ; anthers purple. 



Creeks near Mount Lofty. Aug. -Nov. — South Africa. 



