CHAP. II GROWTH-FORMS 9 



Multicipital rhizomes. Herbs with a multicipital rhizome ^ ordin- 

 arily have axes with short internodes which are hypogeous, but often he 

 well above the soil, and, at the bases of the connected stems, usually 

 bear irregularly placed buds, which are protected with bud-scales, and 

 give rise to erect flowering long-shoots and inflorescences. Growth is 

 caespitose : 



On grassland and savannah : Vincetoxicum ofiicinale, Silene inflata, 

 Rheum, Dahlia variabilis (with food-storing roots). 



In savannah-plants the rhizome often becomes a thick, irregularly 

 lignified ' xylopodium '.^ 



Mat-geophytes.^ Perennial spot-bound herbs, mostly monocotylous. 

 The renewal-buds often deeply embedded in the soil on a short-jointed, 

 feebly branched shoot, which usually contains a large amount of food- 

 material. Occurring especially in hot dry lands. Rest during summer. 

 Epigeous vegetative shoot with long internodes or, in some species, with 

 a rosette of leaves 



with stem-tubers : Crocus, Arum maculatum, Amorphophallus, 

 Eranthis hyemalis, species of Corydalis ; 



with root-tubers : Ophrydeae ; 



with bulbs : many Liliaceae and Amaryllidaceae ; 



with perennial tuberous stem : Cyclamen. 



Travelling geophytes (Rhizome-geophytes). Geophytic perennial herbs 

 with horizontal hypogeous branched scaly shoots, from which are emitted 

 either foliage-leaves or erect epigeous shoots that bear foliage and flowers. 

 The renewal-buds are inserted on the hypogeous shoots, and have bud- 

 scales. Great variety is exhibited in the length of the internodes and 

 other details : 



On loose soil of dunes : Ammophila arundinacea, Carex arenaria. 



On loose humus soil in the forest : Polygonatum multiflorum, Anemone 

 nemorosa, Asperula odorata. Zingiber officinale. 



On mud in water or swamp : Phragmites communis, Equisetum 

 limosum, Hippuris vulgaris. 



In some cases the subterranean shoots become more or less tuberous 

 food-reservoirs, and their elongated thin parts are then very short-hved : 

 Solanum tuberosum, Stachys tuberifera. 



Special forms are where 



Epigeous parts are exclusively foliage-leaves : Pteris aquilina. 



Hibernation is by roots : Cirsium arvense. 



{b) Rosette-plants. The erect foliaged shoot has short internodes 

 and consequently closely set leaves ; it is usually epigeous and evergreen 

 with naked buds, although often only the youngest leaves remain fresh and, 

 in winter, are protected by the old faded foliage. The type occurs on 



Open land (grassland, moors, arctic heaths, and so forth) : 



Arctic and alpine fell-fields : Papaver nudicaule and Draba. 



In the cold-temperate chmate there are many rosette-herbs, including 

 those : 



With leaves sessile elongated : Plantago major, Armeria vulgaris, 

 Taraxacum vulgare ; 



' 'Crown-formers' (Hitchcock) (1898); also see Pound and Clements, 1898, 

 p. 106 ; Drude, 1896, p. 48. 



' Lindman, 1900 ; also see Warming, 1892. ' See Raunkiiir, 1905, 1907. 



