Submerged marine plant; rhizome thick, creeping; branches short, terminated by narrow-linear leaves with stipular sheaths, denticulate upwards, 9-13 nerved. Infl. monœcious, axillary. Male fl. long peduncled, longer than leaves; per. 0; anthers 2, connate, stipitate. Fem. fl. carpels 2, subovoid, strongly keeled, acute, dentate. Red Sea Prov. (Suakin & Dongonab). =C. serrulata= _Aschers._ & _Magnus._ Leaves almost straight, 4-6 in. long and up to ⅓ in. broad; tip entire or denticulate; nerves ab. 7 pairs; sheaths as broad as the blade. Red Sea Prov. (Suakin & Dongonab). =C. ciliata= _Ehrenb._ Stem 3-12 in. long, woody, branched, marked with annular scars. Leaves lin.-falcate, 3-6 in. long, ½-⅔ in. broad, tip rounded, ciliate- serrulate. Red Sea Prov. (Abu Hamir near Dongonab). =C. isoëtifolia= _Aschers._ Stem short, filiform. Leaves terete, grooved, 3-5 in. long, slender; tip. 3-toothed. Fl. in dichotomous cymes. Red Sea Prov. (Suakin northwards). =C. sp.= Leaves broad-linear; stipular sheaths transparent, chartaceous. Red Sea Prov. (Dongonab). =TYPHACEÆ.= 738 =Typha angustata= _Bory_ & _Chaub._ BURDI & DIS—Arab. Marsh or aquatic herb. Leaves alt., strap-shaped, ⅙-½ in. broad. Flowering stem erect, terminated by a dense, felt-like cylindrical spike, interrupted at or below the middle by a naked space, ¼-1 in. long, the upper spike being male and the lower female. Male fl.: sta. 3; filam. connate; fem. fl. mingled with bracteoles, clavate or spathulate much longer than surrounding hairs. Nubia; Blue Nile, White Nile & Kordofan Provinces. =T. angustifolia= _Linn._ Marsh herb, 5-6 ft. high. Leaves linear, ⅓-⅓ in. broad. Male portion of spike longer than and ¼-1½ in. distant from fem. portion of spike. Male fl. with forked, acute, or entire spathulate bracteoles. Fem. fl. with orbicular-spathulate, obovate or obcordate bracteoles about as long as the surrounding hairs. Red Sea Prov. (24 miles West of Suakin). The fibrous leaves are used for matting, ropes, baskets and also for paper-making. =T. australis= _Schum._ & _Thonn._ Leaves linear or strap-shaped, ¼-½ in. broad. Male and fem. portions of spike subequal, contiguous to 1 in. distant. Male bracteoles variously shaped, entire or 2-3 forked. Fem. bracteoles as long as, or slightly longer than hairs and lanceolate-spathulate, sometimes fusiform-clavate, acute or acuminate. Bahr El Ghazal Prov.; Bahr El Jebel (Sudd). =ARACEÆ.= 739 =Pistia Stratiotes= _Linn._ EL TŪBBUR (Kordn.)—Arab; KOF—Nuer; PANGBADUPER—Zande. The Water-Lettuce. Gregarious, floating, stemless, monœcious herb, with tufted root-fibres. Leaves sessile in a rosette forming a cup; nerves radiating from base. Spathe small with spadix adnate to back of its short tube. Male infl. a whorl of 2-8 connate anthers near top of spadix. Fem. fl. of a single ovary, apparently arising from back of the spathe.