CYATHEA 



CYCAS 



931 



1179. Fruiting pinnule of 

 Cyathea meridensis. 



A. Rachides unarmed: Ivs. white beneath. 

 dealbata, Swartz. Rachides with pale rusty wool 

 when young: Ivs. firm, bi-tripinnate, almost pure white 

 beneath. New Zeal. C. Smithii, Hort., is regarded by 

 some as a horticultural variety. 



AA. Rachides unarmed: Ivs. green beneath. 

 Burkei, Hook. Stalks with tubercles near the base 

 bearing large, glossy rusty scales: Ivs. bipinnate, with 

 broad pinnules. S. Afr. 



meridensis, Karst. Figs. 

 1178,1179. Lvs. tripinnatifid, 

 with oblong-lanceolate pinnae 

 and rather narrow lanceolate 

 pinnules; segms. scaly on the 

 ribs beneath. Colombia. 



AAA. Rachides spiny: Ivs. 



green beneath. 

 medullaris, Swartz. Lvs. bi-tripinnate, densely scaly 

 when young, with soft, deciduous hair-like scales; 

 segms. coarsely serrate or pinnatifid, on spore-bearing 

 Ivs. New Zeal. 



C. angolensis, Welw. A greenhouse species said to have 

 fronds 6-8 ft. long produced from a trunk which attains 12-15 ft. 



L. M. UNDERWOOD. 



C^CAS (Greek kukas, the name of a palm tree). 

 Cycaddcese. Several beautiful palm-like plants, com- 

 mon in cultivation under glass. Plate XXXIII. 



The Cycadaceae are of great interest because they 

 occupy a place intermediate between flowering plants 

 and the cryptogams. Like the former they have fr. 

 with a large starchy endocarp; but like the latter their 

 sexual prop, is accomplished by means of sperma- 

 tozoids and archegonia, corresponding to the male 

 and female elements in animals. The plants are dioe- 

 cious; the male inn. is in the form of an erect cone 

 composed of modified staminal Ivs. which bear on the 

 under surface globose pollen sacs corresponding to 

 microsporangia; the female infl. consists of a tuft of 

 spreading carpellary Ivs. having their margins coarsely 

 notched; in the notches are situated the ovules, which 

 are devoid of any protective covering, and correspond 

 to macrosporangia. Pollination under natural condi- 

 tions is effected by the wind. The pollen settles on the 

 ovules and sends down a tube into the tissue of the 

 nucellus. Archegonia are formed; egg-cells develop, 

 and in the pollen-tube are produced spermatozoids 

 provided with minute movable cilia by which they are 

 propelled, very much as in the spermatozoa of animals. 

 These are discharged over the archegonia and fecun- 

 date the egg. The discovery of spermatozoids in the 

 cycads was made by a Japanese student, S. Ikeno, 

 while investigating the process of reproduction of 

 Cycas circinalis. Those of Zamia, endemic in Fla., 

 were described and figured by H. J. Webber, who 

 found the mature spermatozoids of the latter genus to 

 be the largest known to occur in any plant or animal. 



Most of the species of Cycas are arborescent, having 

 a trunk marked with rings of growth and with the 

 scars of fallen petioles. The trunk is usually simple and 

 columnar (though sometimes it is branched), and is 

 elongated by a terminal bud. The pinnate leaves Jorm 

 a beautiful terminal crown like that of a palm or tree- 

 fern. Cycads are found among the fossils of many 

 geological formations, especially in those of the early 

 Mesozoic. The latter formations are grouped together 

 on this account, and the geological epoch which they 

 represent is sometimes designated as the "Age of the 

 Cycads." 



Cycads are among the most ornamental plants of 

 tropical and subtropical gardens. In the United States 

 they are often designated "sago palms," although they 

 have nothing in common with a palm except the general 

 habit of growth. In Florida, according to H. Nehrling 

 who has a plantation at Gotha, near the center of the 



state, they thrive equally well on high pine land and 

 in the rich soil of the low hummocks. C. circinalis is 

 apparently the most sturdy of the cultivated species. 

 It is almost free from diseases; but it is more sensitive 

 to cold than C. revoluta. The latter, on the other hand, 

 is subject to diseases in low flat wooded situations. 

 A third species, C. siamensis, which is comparatively 

 rare, seems to be perfectly hardy in Florida. In cultiva- 

 ting cycads, Nehrling has attained the best results by 

 keeping the weeds away from the base of the trees and 

 loosening the soil from time to time, taking care not 

 to injure the small network of tubercle-bearing roots 

 surrounding the trunk. The tubercles, which are 

 about the size of a pea, are interesting to the plant 

 physiologist, and are apparently conducive to the 

 plant's well-being. Nehrling gathers the pollen from 

 the male plants and sprinkles it by hand over the 

 female flowers to insure fertilization of the naked ovules. 



Plants are propagated by seeds, which keep well for 

 a month or more after ripening. According to E. N. 

 Reasoner, they should be sown in shallow boxes or the 

 greenhouse bench, lightly covered with sand, and after 

 germination, potted off in small pots of moderately 

 rich, light soil. The growing plants ,.do best in partial 

 shade. The old plants frequently send up suckers around 

 the base of the trunk. These may be taken off when in 

 a dormant state and rooted, care being taken to remove 

 the leaves to guard against excessive transpiration. 

 Growing cycads require sunshine and moisture. 



The beautiful glossy leaves of cycads are used in 

 many countries for ornamenting temples and for decora- 

 ting altars. On the island of Guam they are used for 

 palm leaves on Palm Sunday, and in the early days 

 they were carried by children in religious processions, 

 marching from one village to another under the guid- 

 ance of the Jesuit missionaries. Cycads are popular 

 conservatory plants, of easy culture, and tenacious of 

 life, even when neglected for a long time. Their stems 



1180. Cycas pectinata. 



deprived of leaves are easily transported in bulk 

 and will soon resume growth when planted. In the 

 southern United States, cycads are injured by frost but 

 often revive after having apparently been killed. 



A. Margins of pinnse flat. 

 B. Modified fr. -bearing Ivs. (carpophylls) spinous- 



toothed along the margin. 



c. Scales of male infl. tapering into a long spine. 

 D. Lvs. 5-8 feet long, with pinnae 10-12 in. long. 



circinalis, Linn. (C. Thoudrsii, R. Br.). FERN PALM. 

 A palm-like tree with cylindrical trunk and a crown of 



