46 TYPHACEAE. 1. Typha. 



Family 13.— TYPHACEAE. 



Flowers monoecious, without perianth, arranged in dense cylindrical spikes, the upper 

 male, the lower female ; stamens 2-5, often united towards base ; ovary stalked, with 

 1 persistant style and unilateral stigma ; fruit a small nut with 1 pendulous albuminous 

 seed ; testa membranous ; radicle superior. Water-plants. 



1. TYPHA, L. 



(Greek typhe, name of the plant.) 



1. T. angustifolia, L. Bulrush. Stems erect, reed-like, 1-2 m. high ; leaves long, 

 stiff, 6-8 mm. broad ; spikes separated by an interval of about 3 cm., the female one 

 12-25 cm. long and finally over 2 cm. thick, velvety owing to the tufts of long hairs growing 

 on the slender stalk of the fusiform fruit ; anthers 2-3, inserted on a common filament. 



T. Muelleri, Rohrb, and T. Basedowii, Graebn. (the latter from the Flinders Range) 

 appear to be forms of T. angustifolia marked by trifling variations in the hairs at the base 

 of the stamens. 



A perennial aquatic cosmopolitan plant, found growing near water in most parts of 

 the State. Nov. -Dec. 



Family 14.— POTAMOGETONACEAE. 



Flowers bisexual or unisexual, solitary or in spikes ; perianth of 4 herbaceous segments 

 or often wanting ; stamens 1-4 ; carpels 1-8, each with 1 pendulous ovule ; fruit usually 

 hard, indehiscent, 1 -seeded. Water plants, often with very long stems, so as to enable 

 the flowers and floating leaves to emerge. 



A. Flowers unisexual, enclosed in a leaf sheath. 



B. Flowers monoecious, spicate Zostera 1. 



B. Flowers dioecious, solitary. 



Anthers and carpels 2 ; leaves linear Cymodocea 2. 



Anthers and carpels 3 ; leaves capillary Althenia 3. 



A. Flowers bisexual. 



C. Flowers in compound spikes Posidonia 4. 



C. Flowers in simple pedunculate spikes. 



Perianth of 4 segments Potamogeton 5. 



Perianth none Ruppia 6. 



1. ZOSTERA, L. 

 (Greek zoster, a girdle : alluding to the ribbon -like leaves.) 

 Flowers unisexual, male and female in alternate rows forming a flat spike enclosed in 

 the sheathing base of the floral leaf ; no perianth ; male flowers of 1 subsessile, 1 -celled 

 anther ; pollen filiform ; female flowers of 1 carpel, attached laterally, with a filiform 

 2-branched style ; ovule 1, pendulous. Submarine plants, with a creeping rhizome 

 and long, grass-like, alternate leaves. 



Leaves notched at summit Z. nana 1. 



Leaves rounded at summit Z. tasmanica 2. 



1. Z. nana, Roth. Leaves narrow, linear, about 2 mm. broad, bluntly notched at summit, 

 with 1 cental nerve, 2 marginal nerves and 4-6 fine secondary nerves ; flowers with 

 bracteoles ; fruits smooth. — Z. Muelleri, Irmisch. 



Sea-coast. Dec. -Feb. 



2. Z. tasmanica, G. V. Martens. Leaves rather broader, rounded at summit or minutely 

 notched ; flowers without bracteoles ; fruits striate. 



Sea-coast. 



2. CYMODOCEA, Koen. 

 (Greek Kymodoke, name of a sea-nymph.) 



1. C. antarctica (Labill.), Endl. Submarine plant ; rhizome creeping and producing 

 upright shoots at the nodes ; leaves distichous, broadly linear (2-7 cm. long, 4-8 mm. 

 broad) truncate or lunate at the summit ; flowers solitary, enclosed in the sheathing 

 base of the leaf ; male flowers naked ; anthers 2, 4-celled, shortly horned at summit, 

 coherent, inserted on a common stalk ; pollen filiform ; female flower consisting of twin 

 carpels more or less surrounded by a cup formed of connate membranous bracteoles 

 (perianth ?) ; style with 3 stigmatic branches ; fruiting carpel a drupe, the horny endocarp 

 becoming a 4-lobed comb-like cup ; embryo germinating within the carpel and producing 

 a young plant which finally breaks away from the branch, along with the " comb," and 

 roots at the bottom of the sea. — Pectinella antar tica, J. M. Black. 



Sea-coast. One of the " sea-grasses " and often cast ashore. Sept. -Jan. 



