LICUALA 



LIGHT 



1855 



Propagation is by fresh seeds, over brisk bottom heat, 

 preferably in pans. (W. H. Taplin.) 



A. Lvs. with lobes more or less grown together; lobes 



very broad. 

 B. Marginal teeth very large, the upper edges bent under. 



Rumphii, Blume. Not unlike L. spinosa, but the 

 petiole spiny below: segms. 12-15, the inner ones 2 ft. 

 long and 1 ft. wide at the apex, the lateral ones 16 in. 

 long and 4 in. wide, oblique; marginal teeth broadly 

 ovate, obtuse, shortly bifid. Celebes and Borneo. Cult. 

 in S. Fla. 



BB. Marginal teeth with upper edges not bent under. 



grandis, Wendl. (Pritchdrdia grdndis, Bull). Erect 

 palm, the sts. clothed above with dead sheaths: Ivs. 

 very many, erect-spreading; petiole 3 ft., slender, gla- 

 brous, with stout, short, straight or curved spines along 

 the margins below the middle; blade orbicular or semi- 

 orbicular, very closely plicate, wedge-shaped or trun- 

 cate at the base, concave, the margins with many 

 short lobes which are obtusely 2-fid; ligule thick, short, 

 acute, broadly ovate. New Britain Isl., north of New 

 Guinea. I.H. 28:412 and 41, p. 82. G.C. II. 1:415. 

 B.M.6704. A.F. 7:1145. F.E. 7:982. S.H. 1:344. 

 G. 10:439. R.B. 37, p. 24. 



AA. Lvs. digitately divided; lobes narrow. 

 B. Lobes less than 12. 



Jeanenceyi, Sander. A dwarf, rapidly growing palm: 

 Ivs. deep shining green; lobes blunt, 5-8. New Guinea. 

 Gn. 55, p. 71. F.E. 11:291. G.M. 41:341. A.G. 22: 

 651. This palm is known only in its sterile, young 

 condition, and its relationship is in doubt. The name 

 "Jeanenceyi" appears to be unknown in botanical liter- 

 ature. The plant is an attractive addition. 



BB. Lobes 12 or more. 



c. Petioles without spines in the upper part. 

 elegans, Blume. Sts. thick as a man's body, 4 ft. 

 high, prominently scarred: petioles 3-4 % ft. long, the 

 margins with brown hooked spines to just above the 

 middle; Ivs. orbicular; lobes very graceful, the linear- 

 lanceolate lateral ones gradually decreasing to 11 in., 

 obliquely truncate, with acute teeth, the middle lobes 

 16 in. long, truncate, with broader obliquely ovate 

 obtuse teeth, lobes with only 2 or 3 folds. Sumatra. 



cc. Petioles spiny throughout. 

 D. Lvs. ascending. 



peltata, Roxbg. Fig. 2143 (redrawn from Martius). 

 Lvs. 3-5 ft. diam., orbicular; lobes very variable in 

 length and width, many-toothed at the apex, the teeth 

 J^-2 in.; petiole stout, 3-4 ft. long. The lobes of the 

 Ivs. droop very gracefully. India. G.C. 1872 : 1657. 



amplifrons, Miq. Lvs. 23^ ft. long, the tip ascend- 

 ing: blade usually about 12-parted, many of the divi- 

 sions 2-lobed at the apex: spadix long and stiff, reddish 

 brown: fls. and fr. unknown. Sumatra. Not common 

 in cult. 



DD. Lvs. horizontally spreading. 



spinosa, Thunb. (L. hdrrida, Blume). Lvs. 3 ft. or 

 more diam., orbicular-reniform ; inner lobes 18-22 in. 

 long, 4^-5 in. wide at the apex, 10-1 1-toothed ; outer 

 lobes 15 in. long, 1^-2 in. wide, 4-6-toothed; teeth 

 rather large, triangular-ovate, bifid; petioles obtusely 

 3-angled, 4-5 ft. long, with brownish hooked spines. 

 Java, Moluccas. JARED G. SMITH. 



N. TAYLOR.! 



LIDBECKIA (Eric Gustavius Lidbeck, Swedish 

 botanist; published about 1750-1760). Composite. 

 Two S. African subshrubs or semi-herbaceous plants, 

 sometimes grown in greenhouses and suitable for the 

 open far S. Lvs. alternate, lobed or pinnatifid: pedun- 

 cles 1-headed, the disk yellow and rays white; ray- 



florets neuter; disk-florets perfect, tubular; receptacle 

 flattish; bracts of involucre in 2-3 series: achene gla- 

 brous, wingless and without pappus but crowned by a 

 cylindrical nectary. Prop, by seeds when procurable, 

 and by cuttings. L. lobdta, Thunb. (Cotula lobata, Hort. 

 C. quinqueloba, Linn, f.), is silky villous, 1-2 ft. high: 

 Ivs. petiolate, 3-5-lobed, the lobes broad-oblong and 

 mucronate: involucre very hairy. L. pectinata, Bergius, 

 is glabrate or sparingly pubescent, 2-3 ft. high: Ivs. 

 nearly sessile, oblong, pinnatifid, glaucous beneath: 

 heads larger than in the last, resembling Chrysanthe- 

 mum Leucanthemum, the peduncles 1-3 in. long. 



LIGHT. The various manifestations of energy which 

 we term heat, light, electricity, gravitation, and the 

 like, play an important role on living matter, and none 

 is more important than light. Photosynthesis or carbon- 

 assimilation, a characteristic plant function, constitutes 

 one of the fundamental processes in nature; indeed this 

 process, which in remote ages may have been developed 

 secondarily as a protoplasmic function, is as wonderfu 

 as life itself, and a thorough comprehension of photosyn- 

 thesis would appear to be as difficult as that of life. 

 However, no form of energy affects plant configuration 

 more than light, and in the growing of crops, whether 



2144. Showing longitudinal and cross sections of a greenhouse 

 with partitions running north and south, and illustrating the effect 

 of poor light conditions. The oblique lines represent the path of 

 the sun's rays. 



out-of-doors or in the greenhouse, the factor, light, 

 must always be given consideration. 



Light is regarded as a form of radiant energy and is 

 composed of various wave-lengths of exceedingly small 

 size. Those which are especially active in photosynthe- 

 sis or carbon-assimilation in our common green plants 

 are in the red half of the spectrum, while the blue- 

 green pigment organisms (marine algae, and the like) 

 utilize the more highly refrangible rays of the spectrum. 

 Briefly, photosynthesis is the building up of carbohy- 

 drates from carbon dioxide and water through the 

 chemical action of light on the chlorophyll, and since 

 plants obtain most of their energy by means of this 

 process, it is not difficult to realize its fundamental 

 significance and importance. The ultimate product of 

 photosynthesis is starch, but the complex chemical 

 changes taking place in chlorophyll grains through the 

 action of light and the building of starch from carbon 

 dioxide and water is not definitely known, and there 

 are doubtless many intermediate steps. 



In any examination of flora is found much variation 

 and adaptability to conditions, the result of innumera- 

 ble generations existing under varied conditions. The 

 light conditions in one section differ greatly from those 

 in another part of the earth, but it is known from actual 

 observation that some plants require much more light 

 than others for their normal development. Even in the 

 same location, such as the tropics, remarkable differ- 

 ences may be found in the light requirements. Many 

 tropical plants require little light, and even when grown 

 in northern latitudes in conservatories they require 

 shading throughout the year. Palms, geraniums and 

 other plants will develop normally under far less light 



