j CURV] 



5Fi)e Creagttry ol 3Bfltang. 



364 



or assagays : hence the common name As- [ Aiate the evil. The extent of the mischief 



sagay Tree. [G. D.] may he judged from the fact that it Mas 



„ TT „„ imT , T „ ,^ , . reported in the Agricultural Gazette for 1859 



CURVATIVE. When the margins are that one grower of flax had separated no 



slightly turned up or down, without any 



sensible bending inwards. 

 CURVE-RIBBED. When the ribs of a 



leaf describe curves, and meet at the point ; 



as in Plantago lanceolata. 



CURVINERVED, CURVE-VEINED. The 



same as Convergenti-nervose. 



CUSCO BARK. A kind of cinchona 



hark. 



CUSCUTACE^E. (Dodders.) A natural 

 order of corollifloral dicotyledons, belong- 

 ing to Lindley's solanal alliance. The 

 plants are included by some in a suborder 

 of Convolvulacece. Leafless parasitic twin- 

 ing herbs, with flowers in dense clusters. 

 Calyx inferior, four to five-parted ; corolla 

 persistent, four to five-cleft ; scales alter- 

 nating with the segments of the corolla, 

 and adhering to them ; stamens four to 

 five ; ovary two-celled, with two ovules in 

 each cavity ; styles two or wanting ; fruit 

 two-celled, either capsular or succulent : 

 seeds with fleshy albumen ; embryo spiral, 

 filiform, having no cotyledons. The seeds 

 germinate in the soil in the usual way, and 

 afterwards become true parasites by attach- 

 ing themselves to plants in their vicinity, 

 and growing at their expense. Some of 

 them destroy flax, clover, and other crops. 

 Dodder, or scaldweed, is also the pest of 



: beans and hops in some places. These 



; parasites are found in the temperate re- 



| gions of both hemispheres. They seem 

 also to possess acrid and purgative quali- 

 ties. The farmer requires to take care 

 that dodder seeds are not mixed with 

 those of his crops. They may be separated 

 by careful sifting. There are upwards of 

 fifty species included in four genera, of 

 which Cuscuta, Lepidanche, and Epiliiwlla 

 are examples. [J. H. B.] 



CUSCUTA. The Dodders, a genus of 

 annual leafless parasitic plants, the stems 

 of which consist of small wh-e-like tendrils 

 that twine round the plant destined to be 

 the foster parent, and into the texture of 

 which they send out aerial roots at the 

 points of contact, and through these im- 

 bibe the sap of the attacked plant. Our 

 native flora contains two species : C. euro- 

 pwa, a plant which is described by Sir J. 

 Smith as climbing ' two or more feet high 

 upon thistles, oats, and any plants that are 

 crowded together and will afford it nourish- 

 ment ;' and C. Epithymum, a smaller plant 

 which grows on heath, thyme, &c. Besides 

 these are now recognised C. Epilinum, the 

 Flax Dodder, and C.Trifolii, the Clover Dod- 

 der, species, or probably varieties, which it 

 would appear have been introduced with 

 foreign seeds of their respective crops in 

 the cultivation of which they are so gradu- 

 ally becoming most serious impediments. 

 This is so much the case that we were in- 

 duced to experiment largely on their mode 

 of growth, with a view if possible to ob- 



Cuscuta Epilinum. 



less than seventy bushels of Dodder seed 

 from his flax crop. With some of this 

 seed we carried out the following experi- 

 ments :— 



Exp. 1.— On sowing some seeds in a sau- 

 cer with fine mould, the following ap- 

 pearances presented themselves. In four 

 days, the radicle was extended. In five 

 days the germ was elevated above the soil, 

 bearing the seed-covering on its apex. In 

 six days the young thread-like plant was as 

 it were on the look-out for a foster parent, 

 and by the eighth day, not finding a foster 

 parent, it emerged from the soil and died. 

 (See diagrams in Agric. Gaz. 1859, 746.) 

 Thus, then, all the plants which germinated 

 freely died within a few days, the thread- 

 like germs gradually becoming elevated out 

 of the soil, and then withering away. How- 

 ever, on planting young examples of flax, 

 chickweed, tomato, and others among 

 them, the later germinated seeds immedi- 

 ately directed their threads towards them, 

 and commenced that parasitic mode of 

 growth which was so fully shown in the 

 next case. 



Exp. 2.— A saucer was sown with a mix- 

 ture of flax and Dodder. In a few days 

 both germinated, and the Dodder threads 

 were attracted to the stems of the young 

 flax, their history and progress being as 

 follows. In seven days the Dodder had 

 just clasped a flax plant. In nine days, 

 both Dodder and flax having grown, the 

 elevation of the flax stem had lifted the 

 firmly attached Dodder out of the soil. In 

 eleven days the Dodder was throwing out 

 buds for new shoots, and the lower un- 

 attached part was dying away. (See dia- 

 gram already referred .to.) This explains the 

 method by which the Dodder first becomes 

 attached to the plant upon which it grows. 

 It makes one or two tight coils around its 

 future support, and during the time these 

 coils are progressing, the foster-parent is 

 increasing in size, the compression of the 

 former around the latter becomes tighter, 

 thus causing the bark of the foster-parent 



