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Transactions of the Royal Society of South Africa. 
Acanthaceae respectively. The ecological factor selected as a basis is the 
degree of lignification and xeromorphy. Thus we can arrange the Nano- 
phanerophytes in a series, showing increased amount of lignification and 
xeromorphy according to variation in the environment, as follows : 
(1) Soft-stemmed herbaceous perennials, with persistent aerial 
parts, e.g. Plnjtolacca sp2^. These are somewhat rare as Nanophanerophytes, 
but abundant as Chamaephytes (vide infra). 
(2) AcANTHACEors Type. — Weakly lignified undershrubs with thin leaves. 
They are commonly shade-loving bush plants, growing in the more open 
parts of the bush, or around the bush margin in a moist habitat. Many of 
them flower in winter, e.g. various species of Acanthaceae, Verbenaceae, 
Labiatae, Piper capense, etc. 
(3) Leguminous Type. — Woody, much-branched shrubs, more charac- 
teristic of open spaces and veld, and often reduced to Chamaephytes by 
grass fires. 
(4) Composite Type. — Shrubby Compositae, etc., often growing rather 
tall, but having various xerophytic modifications, such as thick leaves 
{Osteospermum), dense coating of hairs, etc., particularly abundant on the 
Drakensberg at high altitudes. 
(5) Ericaceous Type (or Heath Type). — Almost too well known to 
require further description. It includes the Ericaceae (eighteen species) as 
well as isolated forms, occurring in widely separated families. Rosaceae 
(Cliffortia), Thymeliaceae (Passerina, Lasiosiplion)- — another Alpine type. 
(6) Succulent Type. — Fleshy plants, with persistent aerial parts over 
25 cm. tall — Aloes and certain Crassulaceae. 
(7) LiANES. — Species of Asclepiadaceae, etc., many of which are also 
Geophytes. The lianes, as in all the other classes, foim a group by them- 
selves. 
The number of intermediate types might be multiplied considerably, but 
it is hardly necessary to do so. Every gradation in xeromorphy is naturally 
shown within the limits of a large class, such as the Nanophanerophytes. 
The types mentioned above simply mark certain definite stages. 
We have now dealt with all the Phanerophytes, and, considering the 
group as a whole, we notice a progressive tendency towards greater protec- 
tion during the adverse season. This is shown by a decrease in size, and 
this simple fact has been selected by Eaunkiaer as a basis for his divisions. 
Further, it is noticeable that Mesophanerophytes tend to be reduced to 
Nanophanerophytes, and these in turn to Chamaephytes. 
It may be remarked here that mere size or rather height is not, in all 
respects, a very satisfactory basis for classification. It is quite true that, 
taking into account only the inorganic factors of the environment, a taller 
plant is less protected than a shorter one, other features being equal. But 
where plants grow in such intimate relationship to one another, as they do 
