252 



HYDROLEACE/E. V. CODON. CONVOLVULACE^E. 



with as many ribs as there are lobes of the limb ; limb 10-12- 

 cleft : lobes oblong, obtuse, keeled, imbricate in aestivation ; 

 alternate ones smaller. Stamens 10-12, alternating with the 

 lobes of the corolla, rising from an equal number of compressedly 

 tetragonal arches, which are inserted in the bottom of the co- 

 rolla ; filaments subulate, glabrous. Anthers adnate by their 

 middle, incumbent, 2-celled; cells combined at the extremities ; 

 pollen mealy. Style semi-bifid, pilose at the base ; stigmas 

 simple, obtuse. Capsule ovate-acuminated, 2-celled, 2-valved, 

 dehiscing at top. Dissepiment double, with revolute, seminife- 

 rous edges. Seeds numerous, angular, papillose ; testa simple, 

 cartilaginous. Albumen copious, horny. Embryo erect, slender, 

 a little arched, with very short cotyledons, and a long, filiform, 

 obtuse radical, looking to the hylum. This genus agrees with 

 Hydroleacece, although the stamens, and the divisions of the 

 calyx and corolla, are double in number, the symmetry of the 

 flower is preserved ; but this mere increase of parts is of little 

 importance, when the number of points of agreement are taken 

 into account. In Cbdon, and some of the Hydroleacece, parti- 

 cularly in JVigandia, the leaves have lobed margins, and are 

 clothed with bristly points, which in the former genus are deve- 

 loped into prickles. The stamina and pistilla entirely agree in 

 both genera ; but the albumen is more copious, and the stigmata 

 less developed in Cbdon, whose affinities, however, to the 

 Hydroleacece, may be considered as completely established. 



1 C. ROYE'NI (Lin. syst. nat. ed. 13. p. 292. Thunb. prod. p. 

 80. Willd. spec. 2. p. 540. Andr. bot. rep. t. 325.) 0. F. 

 Native of the Cape of Good Hope. Codon acule&tum, Gaertn. 

 fruct. 2. p. 88. An annual herb, furnished with copious white, 

 straight, subulate prickles. Root fusiform ? Stem erect, 

 branched, terete, flexuous, robust. Leaves aternate, petiolate, 

 ovate-oblong, a little attenuated towards the apex, but obtuse, 

 thickish, fleshy, and ribbed beneath, with recurved, sub-repand 

 edges. Flowers large, solitary, pedunculate, extra-axillary, 

 somewhat racemose at the top of the stem, usually bracteate by 

 two narrower leaves at the base. Corolla white, variegated with 

 purple. 



Royen's Codon. Fl. Sept. Clt. 1801. PL 1 to 1$ foot. 



Cult. This is a singular plant, the seeds of which should be 

 sown in a pot, in rich, light earth, and the pot placed in a frame ; 

 and when the plants are of sufficient size, they may be moved 

 into separate, small pots, and shifted into other larger ones by 

 degrees, as they grow. They may afterwards be placed among 

 other greenhouse plants. 



ORDER CLXIV. CONVOLVULA'CE^E (this order contains 

 plants agreeing with the genus Convolvulus in important charac- 

 ters.) Juss. gen. p. 132. edit. Usteri. p. 148. R. Br. prod. p. 

 481. H. B. et Kunth, nov. gen. amer. 3. p. 94. Choisy, in 

 mem. soc. phys. gen. 6. p. 383. 



Calyx of 5 sepals (except in Wilsonia, which is gamosepalous 

 and 5-toothed ;) sepals permanent, equal or unequal, disposed in 

 one, two, or three series, often enlarged round the fruit. Corolla 

 monopetalous, hypogynous, regular, tubular, campanulate or 

 funnel-shaped ; having the limb sometimes of 5 plaits, and 

 sometimes of 5 lobes, which are twisted in aestivation. Stamens 

 5, opposite the sepals, and therefore alternating with the lobes or 

 plaits of the corolla, inserted more or less towards the bottom of 

 the corolla ; filaments usually unequal, dilated at the base, some- 

 times villous, naked, or furnished with scales, usually inclosed, 

 rarely exserted ; anthers long, usually sagittate, and adnate at 

 the base, often twisted afterwards. Nectarium or hypogynous 



disk annular, surrounding the ovarium in most of the species, 

 more or less showy. Ovarium usually simple, 2-4-celled, rarely 

 almost 1- celled, or altogether 1 -celled : sometimes the ovarium 

 is double or quadruple ; in each cell there is 1 or 2 erect ovula. 

 Style usually simple, entire, or more or less deeply cleft ; rarely 

 two. Stigmas acute, flattened or globose ; in those with the 

 simple style, 2-lobed. Fruit a capsule or a dry berry, 1-4- 

 celled ; cells 1-2-seeded. Capsule usually dehiscing valvately, 

 rarely transversely. Seeds usually rounded on one side, and 

 flattened on the other, inserted by the base, glabrous or villous; 

 having the testa usually black and hard. Albumen mucilagi- 

 nous. Cotyledons foliaceous, corrugated, except in the genus 

 Maripa, in which they are thick and straight. Radicle incurved, 

 inferior. Stems herbaceous, sufFruticose, fruticose, also arbo- 

 reous ; sometimes erect, sometimes creeping, but for the most 

 part twining. Leaves alternate, simple, entire or lobed, sessile 

 or petiolate. Peduncles axillary or terminal, 1 or many-flowered. 

 Pedicels articulated to the peduncles, usually bibracteate ; brae- 

 teas more or less, approximating the flower, sometimes also in- 

 volving the flower. Roots simple or tuberous, edible or medi- 

 cinal. Juice milky, purgative, often filling the stem. 



Nearly the whole of the Convolvulacece are twining plants, 

 with showy flowers, expanding under the influence of sunshine. 

 A few are shrubs, but the greater part are herbaceous, and very 

 many annual. All parts of the world produce them. Cuscuta 

 is a singular parasite, wholly destitute of leaves. The root of 

 many is filled with a milky, acrid juice, which is very purgative. 

 Scammony, jalap, and some other drugs, are the produce of 

 Convolvulacece. The roots of Ipomcea Jlorida, scoparia, and 

 Qudmoclit, are stimulatory ; that of Ipomce'a Batatas, which is 

 the sweet potato of America and South Europe ; and that of 

 Ipomce~a edulis, are wholesome articles of food. 



Synopsis of the genera. 

 TRIBE I. 



ARGYRE'IES. Embryo cotyledonous. Carpels combined into a 

 simple ovarium. Pericarp baccate, indehiscent. 



1 RIVEA. Ovarium 4-celled ; cells 1 -seeded. 



2 MARIPA. Ovarium 2-celled ; cells 2-seeded. Cotyledons 

 not plicate ? Stigma furrowed. 



3 ARGYRE'IA. Ovarium 2-celled ; cells 2-seeded. Stigma 

 2-lobed ; lobes capitate. Corolla campanulate. 



4 BLINKWORTHIA. Ovarium 2-celled ; cells 2-seeded. Co- 

 rolla urceolate. Calyx calyculate. 



5 HUMBE'RTIA. Ovarium 2-celled ; cells 2-seeded. Stigma 

 hollow-flattened. Stamens exserted. 



6 MOORCROFTIA. Ovarium 2-celled ; cells 1 -seeded. ? Fruit 

 2-seeded. 



TRIBE II. 



CONVOLVU'LE.*;. Embryo cotyledonous. Carpella combined 

 into a simple ovarium. Pericarp capsular, dehiscent. 



1 . Style simple, entire even to the stigma. 



7 QUA'MOCLIT. Ovarium 4-celled; cells 1 -seeded. Corolla 

 tubular. Genitals exserted. 



