HORT 202
GENERAL HORTICULTURE LABORATORY
Lab 2: Recognition of Plant Structures
INTRODUCTION

ROOTS

LEAF MORPHOLOGY LEAF TYPES  MODIFIED
LEAVES
 

STEM MORPHOLOGY 
 

MODIFIED STEMS
 

TYPICAL FLOWERS
 

FRUIT PARTS
 

CLASSIFICATION OF FRUIT

MODIFIED STEMS
thorn a stem modified into a short (usually), sharp point.
(rose,  pyracantha)
Rose
thorn-rose
spur a compressed stem with short internodes, usually bearing leaves, flowers and/or fruit.  Many fruit trees bear flowers and fruit on spur shoots.
(apple, pear )
Pear
spur-pear
cladophyll stems, usually flattened, specialized for photosynthesis.
(cactus)
Cactus
cladophyll-cactus
bulb

 

a specialized storage organ (usually underground) composed of a compressed stem enclosed by fleshy or papery leaves or leaf bases.   a) concentric or tunicate bulb
  b) scale or non-tunicate bulb

  See images below.


a) 
concentric or tunicate
stem enclosed by concentric or sheathing leaves or leaf bases.
(onion, garlic, amaryllis, tulip)
Onion
concentric bulb  onion

b) 
scale or non-tunicate
stem enclosed by separate, thick (usually fleshy) scale-like leaf bases.
(lily)
Easter Lily
scalebulb-lily
pseudobulb thickened bulb-like leaf (or stem) based resembling a bulb.
(orchid)
Orchid
pseudobulb-orchid
corm short, thickened, underground stems with few nodes and short internodes, usually enclosed by dry, scale-like leaves.
(gladiolus, crocus, taro)
Taro
corm Taro
tuber large, undergound storage organs formed by thickening or swelling of the subapical portion of an undergound stem.
(caladium, irish potato, Jerusalem artichoke)
Irish Potatotuber- Irish potato
rhizome horizontal stems, usually thick, that grow partially or entirely underground.
(iris, canna, sansevieria)
Sansevieriarhizome-sanseveria
stolon horizontal stems, usually thin, that grow above ground, and which usually form roots and plantlets at nodes that contact the ground.
(grasses)
Grassstolon-grass
runner a slender stem with elongated internodes.
(strawberry, chlorophytum)
Spider Plantrunner-spiderplant

Return to | Hort 201 Lecture Home Page |202 Lab Home Page |
The General Horticulture Laboratory 2 Homepage, was created by Trisha Blessington Haley and was updated by Michelle Meche.  Any comments or suggestions should be e-mailed to D.W. Reed at e-mail: dwreed@tamu.edu.  If you use any of the instructional material, please give credit to the source. Copyright  D.W. Reed, TAMU.