EUPHORRIACEM. 



151 



VIIT? CALLITRICHE SERIES. 



Callitriche^ (fig. 254-258), which has been considered, not with- 

 out question, as a lessened aquatic type of biovnlate Eu^shorbiacepe, 

 has hermaj^hrodite or more frequently mouoecious or dioecious, dime- 

 rous apetalous flowers. The male flower has two lateral imbricated 



Cullitriche stagnalia. 



m 



Fig. 257. Fruit (4). Pig. 255. Male Fig. 254._Florife- Fig. 256. Female 



flower (4). 



Fig. 258. Long, 

 sect, of fruit. 



monandrous flower (f). rous branch. 



sepals,- and two alternate stamens inserted upon a small conrex recep- 

 tacle or even only one middle stamen. The filaments are free, erect, 

 exserted at an thesis ; the anthers are reniform, dehiscing by a semi- 

 circular lateral cleft *. In the female floAver the perianth, some- 

 times but little developed, is similar to that of the male flower, and 

 the gynpeccum is composed of a free ovary,* with four cells super- 

 posed to the sepals, each divided into two half cells by a false centri- 

 petal partition, surmounted by a style soon divided into two simple, 

 straight lateral brandies, stigmatiferous on their whole surface. In 

 each cell is found two collateral, descendent, anatropous ovules, 

 with niicropyle directed upwards and outwards, the exostome 

 thickened and often surmounted by a small cellular obtiu'ator. In 

 the hermaphrodite flowers there is an ovary with two cells superposed 

 to the sepals, and one or two alternate stamens. The fruit is cap- 

 sular, with two rather thin shells, each divided into half shells, 

 marginato or winged at the back by deduplication of the false par- 

 tition. In each half shell is found a descendent seed with an 



• Oen. n. 13. — Adan8. Fam des PI. ii. 471. 

 —J. Geii. 19.— Lamk. Diet. i. 564; Suppl. 

 ii. 36.— G.i-:rtn. Fnict. i. 330, t. 68— DC. 

 Pi-odr. iii. 70. — Nees, Gcti. ii. 4. — Eniil. 

 Gen. n. 1830.— H. Bn. in Jltdl. Soc. Lot. dt Fr. 

 V. 337; Euphorbiac. 650, t. 21. fig. 28-33.— 

 Clakke in Trans. Linn. Soc. xxii. 411; in 

 Seem. Jouru. of Sot. (1865), 36. — Heoelm. 



Monofjr. der Gatt. Callitricho. Stuttg. (1864). 

 — B. II. Gen. 676, n. 9. 



2 Botanists who consider the flowers naked 

 call tlu-so bracts. 



' There aro certainly two cells, the clefts 

 being confluent at the summit. 



* It has been supposed " adherent," with a 

 calyx having an abortive limb. 



