Pteridoph5^ten. — Floristik etc. 393 



between the lime-sink and Gulf Lammock regions in about lati- 

 tude 28°40'. These grottoes are noted for their rare ferns, some of 

 which are tropical species which do not ränge much further north 

 and some are confined to Florida. Harshberger. 



Bews, J. W., The Growth-Forms ofNatal Plant s. (Trans. 

 Roy. Soc. S. Africa. V. 5. p. 605—636. 1915.) 



An examination ol" the Vegetation of Natal based on C. Raun- 

 kiaer's System of growth-forms and biological spectra. The author 

 recognises that the life histories of Natal plants are still incom- 

 pleteh'- known, but has gathered together the available information 

 and presents this as a provisional analysis. The varied liora and 

 Wide ränge of conditions are seen in the large number (3034) of 

 species, and by the Variation seen in the growth-forms of the same 

 species. Phanerophytes are meagrely represented in the limited 

 forest area, but the mixed character of the woods tends to raise 

 the percentage. Compared with Raunkiaer's normal phanero- 

 phytic spectrum of 6 p. cent, Natal has 3 p. cent. The tree-forms 

 present certain features which are discussed under the headings: 

 Variation in size and form, in foliage, and in pubescence, the deci- 

 duous tendency seen in certain evergreen species as a response to 

 the adversities of a dry winter, thickness of bark,and developm.ent 

 of coppice shoots. The Micvophanerophytes, about 420 species or 14 

 p. cent (normal spectrum 17 p. cent) include a large proportion ot 

 lianes, e. g. Vitis and Ipomaea\ there are considerable variations in 

 the growthform of the same species, and other features ascribed 

 mainly to the coastal climate wilhout frost and the Inland condi- 

 tions with frost; spinosity is discussed in considerable detail. Nano- 

 phanerophytes, about 430 species or 14 p. cent (normal 20 p. cent)^ 

 are grouped as a series based on increasing lignification and xero- 

 morphy: soft-stemmed herbaceous perennials, Acanthaceous, Legu- 

 minous, Composite, Ericaceous, Succulent, and Liane types. Cha- 

 maephytes, excluding Pteridophyta, number 570 or 19 p. cent (normal, 

 9 p. cent). The high percentage is ascribed to the dry winters with 

 absence of prolonged frosts, and intensified by occasional hot winds. 

 The chamaephytic growth-forms are arranged in a series showing 

 progressive adaptation to rigorous conditions: Streptocarpus type, 

 herbaceous chaniaephytes, passive chmnaephytes , cushion plants, 

 active chaniaephytes, fleshy-leaved chamaephytes,, suffruticose cha- 

 niaephytes, and forms almost hemicvyptophytes. The hemicryptophytes 

 include 540 species or 18 p. cent (normal 27 p. cent); Compositae, 

 Gramineae and Cyperaceae make up 340 species. They are mostly 

 plants of the veld, adapted to recovery after the extensive grass 

 fires, and in places frequently burned they tend to replace Chamae- 

 phytes. Geophytes attain a high proportion, especially in the veld, 

 and include 550 species or 18 p. cent (normal 3 p. cent), mainly 

 species of Asclepiadaceae , Orchidaceae , Irideae, AmaryUidaceae , and 

 LiUaceae. HeJophytes and Hydrophytes attain to 5 p. cent (normal 1 

 p. cent), not because Natal is marshy, but because of the number 

 of species present in the numerous vleis or marshes along the 

 river Systems. Therophytes are low in the scale, 6,5 p. cent (nor- 

 mal 13 p. cent), mainly weeds of cultivated land. The climate ot 

 Natal is regarded as mainly chamaephytic and geophytic. 



W. G. Smith. 



