504 OEDER CXIII. — CALLITRICHACE^. 



Genus II.— MACLUTJA. Is:utt. 20—4. 

 (In honor of Wm. Maclure.) 



Flowers dioecious. Fertile flowers collected into a dense 

 head; style 1, long, villous; achenia obovate. compressed, im- 

 bedded in a pulp, all forming a fruit the size of an orange, with 

 an irregular surface. A small tree, with straggling branches. 



1. M. aueantia'cea, (Nutt.) A tree ; branches flexuous, terete. Leaves 

 alternate, entire, with supra-axillary spines, i^/owers axillary. — ^. In 

 the Southwest, on the banks of streams. Osage Oravge. Bow wood. 



Used in forming hedges, an-J ipTomises to be the best plant for the Southern States. 

 It is attacked by no animal, &r.G in a few years forms an impenetrable hedjre The 

 Fig, Ficus carica, belongs t^ OjIS Order. Its fruit con>ists of a succulent hollow re* 

 "ceptacle, inclosing numcrlius hingle-seeded carpels, forming a syconus. 



Order CXIL— PODOSTEMA'CE.E. 



Flowers naked, monoecious, bursting through an irregulaly 

 Itcerated spathe. Stamens hypogyn<Ais, monadelphous, 2 or 

 more, alternately sterile and shorter. Ovary '2-celled, with nu- 

 merous ovules Stigmas 2 — 3. Fruit capsular. Seed nu- 

 merous, minute. Floivcrs minute. Aquatic plants, with capil- 

 lary leaves. 



Genus L— PODOSTE'MUM. Rich, 19—2. 

 (From II.-4, Oteek ^OMS, foot, and stenion, a stamen, from their standing on a foot.) 



Genus the same as the Order. 



1. P. ceratophyl'lum, (Mich.) Stein floating, filiform, stiff, horn-like. 

 J^ejfts alternate, pinnate, many-cleft. Flowers axillary, solitary. Sta- 

 mens 2, affixed to a common pedicel Stigmas 2, sessile. Capsule ovate, 

 2-vaIved, 2-celled, many-seeded. — If. July. In the beds of rivers. 



River-weed. 



Order CXIII.— CALLITRICHA'CE^. 



Flowers perfect or imperfect, with 2 opposite colored bracts. 

 Stamen 1. Anthers reniform, 1 -celled. Ovary solitary, 4- 

 cornered, 4-celled. Ovules solitary. Styles 2, subulate. Stig- 

 mas simple points. Fruit indehiscent, 4-celled, 4-seeded. Seed 

 peltate. Flowers axillary, solitary, very minute. Small aqua- 

 tic, herbaceous plants. 



Genus I.— CALLIT^RICHE. L. 1—2. 



(From the Greek kallos, beauty, and trix, hair 



Genus the same as the Order. 



1. C. heterophtl'la, (Pursh.) Stein floating, creeping, round. Float- 

 ing leaves spatulate, immersed ones linear, all opposite, sessile, entire. 

 Perianth persistent, lanceolate, white. Filament subulate. Stt^les 2, 

 subulate. — U- May — June. Still waters. 



