SPECIAL FORMS. 53 



support. In certain tendrils the attachment to the support is by 

 a sucker-like disc at the apex, as in the Virginia Creeper or 

 Ampelopsis, Fig. 94. 



103. Root-Climbers are those in which the stems produce aerial 

 rootlets (59 a ), which fix themselves to a supporting surface 

 along which the stem creeps or ascends. In this way Trumpet 

 Creeper (Tecoma radicans) , Ivy, and Poison Ivy (Rhus Toxi- 

 codendron) climb extensively. 



104. Stems or branches which neither climb nor stand upright 

 may have their direction or habit of growth expressed by certain 

 adjective terms ; such as 



Ascending or Assurgent, when they rise obliquely upward ; 



Reclining, when from an ascending or erect base the upper 

 part recurves and trails ; 



Decumbent, when trailing along the ground, but with apex 

 assurgent ; 



Procumbent or Prostrate, when lying at length upon the ground ; 



Repent or Creeping^ when growing prostrate on the ground 

 and rooting as they grow. Also applied to similar stems grow- 

 ing under, as well as upon the surface of the soil, as in Couch- 

 Grass and Mint, Fig. 99. 



105. A Sucker (tiurculus) is an ascending stem rising from a 

 subterranean creeping base. The Rose and Raspberry multiply 

 freely by suckers. Such plants are easiest to propagate " by 

 division." 



106. A Stolon is a prostrate or reclined branch which strikes 

 root at the tip, and then develops an ascending growth, which 

 becomes an independent plant. 



107. An Offset is a short stolon or a short sucker. Houseleek 

 (Fig. 9 1 6 ) offers a familiar 



example. By offsets, some 

 herbs, otherwise annuals, are 

 continued from year to year in 

 a vegetative progeny (Lobelia 

 cardinalis, &c.), and peren- ( 

 nials may thus establish colo- 

 nies around a parent individual. 



108. A Runner (Flagellum) 

 is a filiform or very slender 



stolon, naked and tendril-like except at tip, where it roots, 

 develops a bud, and so a new plant. The Strawberiy furnishes 

 the most familiar example. 



FIG. 916. Houseleek (Sempervivum tectoruni ) with offsets. 



