Arum.l MONOECIA — POLYANDRIA. 347 



of the gland, which is not below, but above, the point of insertion of the 

 stamen. 



MONOECIA— POLYANDRIA. 



17. Ceratophyllum. Liim. Hornwort. 



1. C. dtmeTSum, L. (common Hormcort); fruit armed with 2 

 spines near the base and terminated by the curved subulate style. 

 E. Bot. L 947. 



Frequent in slow streams and ditches, i*"/. July, ■y . — Floating. Stem 

 long, slender. Leaves setaceous, whorled,'2 or 3 times forked, distantly 

 serrated. Flowers small, whorled in the axils of the loaves. Anthers 

 sessile, crowded, spotted, 2-beaked, 2-celled. — The foliage of this plant 

 is often inflated and jointed, so as to look like a Conferva. 



2. C. siibmersum, \j. (unarmed Hornicort); fruit without spines. 

 E. Bot. t.679. 



Ditches, in the east and south of England, Fl. Sept. !(.. — Scarcely 

 different from the preceding, but in the absence of spines on the fruit. 



18. JMyriofhyllum. Linti. Water-Milfoil. 



1. M. spicdtum, L. (spiked Water -3Iilf oil); sterile flowers form- 

 ing an interrupted leafless spike. E. Bot. t. 83. 



Ditches and stagnant waters. Fl. July, Aug. ![..— Stems slender, 

 much branched. Leaves 4 in a whorl, finely pectinated and always sub- 

 merged. Spikes slender, 3 — 5 inches long. 



2. M. verticilldtum, L. (lohorled Water- Milfoil); flowers all 

 axillary. E. Bot. t. 218. 



Ponds and ditches in Norfolkand Cambridgeshire; Cheshire and Angle- 

 sea. FL Jul}- 14' 



19. Sagittaria. Linn. Arrow-head. 



1. S. sagittifolia, L. (common Arrow-head) ; leaves arrow-shap- 

 ed, the lobes lanceolate straight. E. Bot. t. 84. 



Ditches and margins of rivers of England and Ireland. Fl. July, Aug. 

 If. — A beautiful aquatic, with large, truly arrow-shaped leaves, rising 

 above the sui'face of the water. 



20. Arum. Linn. Cuckow-pint. 



1. A. mactddtum, L. (Cuckow-pint or Wake-robin); leaves all 

 radical hastato-sagittate, lobes deflexed, spadix club-shaped ob- 

 tuse shorter than the spatha. E. Bot. t. 1298. 



Groves and hedges, frequent in England; rare in Scotland and Ire- 

 land. Fl. April, May. 1^ . — Root a tuber, affording an abundant amyla- 

 ceous substance ; which, if properly prepared and the acrid juice ex- 

 pressed, proves an excellent substitute for bread-flour, and is sold for 

 that purpose in great quantities at Wej^moiith and in Portland Island. 

 Leaves large, shining, often spotted with black. Spatha large, convolute. 

 Above the germens, on the spadix, is a ring or circle of 2-celled, sessile 

 anthers, and above these, another ring of apparently imperfect ^e?-wen5. 

 The extremity of the spadix is purplish. Berries remaining during 

 winter, after the leaves and spadix have decayed, crowded into an oblong 

 spike of a bright scarlet colour. 



