THE PF,ANT ECOL()(;V OF 'I'llK COAST liELT OF NA'l'AI-. o9T 



of fixed saii(l-(l Mill's tlic following species form extensive- 

 colonies, consocies or associes. Most of them are wide-sjiread 

 strand plants of tropicnl and sub-tropical regions and such 

 are most abundant. The subordinate species are more often 

 endemic or at any rate restricted in their distribution. 



(a) Hydrophylax carnosa (Rubiacefe) (text-fig. 1, a). 

 — This plant is abundant right along the coast. At certain, 

 places, e. g. Amanziuitoti, Umgababa, Umhloti, etc., it forms 

 pure consocies close to the sea, its fleshy, horizontal creeping 

 stems covering long stretches of the sandy beach (PI. XXII, 

 fig. 1). 



(b) Sctevola lobelia (G-oodenoviete) (text-fig. 1, n). — 

 At Amanzimtoti thi.s species is dominant behind and above 

 the Hydrophylax. Elsewhere, e.g. north of Durban,, 

 it is dominant near the water and sometimes becomes sub- 

 merged at high tides. It has thick, fleshy leaves and long 

 rhizomes whicli creep through the sand, only the leaf-bearing 

 shoots appearing above it (PI. XXII, fig. 2). Cyperus- 

 natalensis is often associated with it, travelling for long 

 distances through the sand. 



(c) Ipomtea ])es-capra? (I. biloba) (text-fig. 1, c). — 

 This species prefers to creep over the sand, but it often 

 becomes buried where the sand is drifting. It occurs all 

 along the coast, being a very connnon tropical strand plant, 

 the ecology of which has been dealt with by tSchimper.^ 

 Iponia3a consocies usually stand considerably higher on the 

 beach than the Hydrophylax or Scasvola types (PI. XXIL 

 fig. 1). 



(d) Mesembryanthenium edule. — -It forms a dense, 

 succulent covering over the surface of the partially fixed 

 sand near the margin of the zone of halophytic shrubs and. 

 herbs, which is transitional to the psamniophilous bush. It 

 is one of the most important sand-fixing- species. 



(e) S p o r o b o 1 u s p u n g e n s . — This widely-distri buted sen - 

 shore grass forms dense consocies and gathers soil so as to- 

 produce hard flat mounds in the transitional belt or even 



' Sclihnper, A. F. W.. "Die iudo-malayisclie straiidflora," 1891. 



