216 HEXANDRIA. MONOGYNIA. 



unequally inserted, 3 of them upon the summit 

 of the tube. Utriculus muricate, l-seeded. 



Aquatic plants; leaves partly radical, of a form betwixt 

 cordate and sag-ittate; scapes unifoliate; flowers ag-gi-e- 

 gated in spikes, or fastigiated in unequal umbells, colour 

 blue, upper lip marked with a discoloured spot. 



Species. 1. P. cordata. Hab. Chiefly within the limits 

 of tide-water, throughout the Atlantic coast. Obs. Leaves 

 sheatliing-, sheath entire; petiole about one third the 

 length of the leaf. Spike at first protected by an ovate 

 spathe, pubescent. Flowers aggregated by o's and 4's, 

 sessile, bilabiate, upi)er lip flat, 3-toothed, blue with a 

 greenish variolate spot in the centre; lower lip 3-parted; 

 tube curved, about equal in length with the limh, marked 

 with 6 longitudinal stri?e, and on the under side singularly 

 perforated with 3 gashes or longitudinal foramina. Sta- 

 mina 6, 3 near tjie base and 3 towards the summit of tiie 

 tube; the 3 exserted stamina of the lower lip variable ia 

 length. Style filiform, blue, marescent with the corolla 

 and usually about its length, shortest when the stamina 

 are most exserted; stigma entire, minute. Germ rather 

 gibbous, ovate, l-seeded. Fruit a l-seeded, greenish, mu- 

 ricated utriculus formed by the persistent calicine base of 

 the corolla; cr.stated ndges of the fruit 6- Perisperm 

 ovoid, conic, very white, sweet and farinaceous, (probably 

 nutritious.) Corculum in the axis of the perisperm, cylin- 

 dric, inverted, (or witii the radical upwards); gemmula t 

 oval, conspicuous. 



2. angiistifoUa. Pursh. Flor. Am. 1. p. 224. Leaves 

 acute, elongated-triangular, base truncate-subcordate, seg- 

 ments of the lower lip of the corolla linear-lanceoUte — In 

 subalpine lakes on the Alleghany mouutains. New York, 

 &c. P. mucronata? llafinesque New York, Med. Repos- 

 2. p. 352. 



3. * lanceolata. Leaf narrow, oblong'-lanceolate, obtuse, 

 base entire, petiole very short; spike siiort. Hab. Near 

 Savannah in Georgia — Dr. \V. Baldwyn. Also in South 

 Carolina. Scape less than afoot long; spathe very obtuse. 

 Leaf nearly a span long, about an inch wide, very opaque, 

 in P. cordata the leaf is diaphanous when held to the light. 

 Corolla blue, segments of the lower lip linear, longer tlian 



t JAttle bndf this word is used here to distinguish betwixt 

 true «nd apparent cotyledones, in the present plant there is no 

 proper cotyledones, merely a, minute bud similar to the per- 

 fect plants 



