University of Florida

Plant Identification Learning Module
Glossary of Botanical Terms: O–R


A–D

E–N

O–R

S–W

 

O

Oblanceolate Leaf Shape: The reverse of lanceolate, with the broadest half above the middle and tapering toward the apex. See Figure 15.
oblance Figure 15.

 

Oblate: Spherical, flattened on both ends.

 

Oblong: Longer than broad, and with the sides nearly parallel. See Figure 16.
oblong Figure 16.

 

Obovate: Inversely ovate, with the broadest half above the middle. See Figure 17.
obovate Figure 17.

 

Odd-pinnately Compound: A compound leaf terminated by a leaflet. See Figure 18.
oddpin Figure 18.

 

Opposite Leaf Arrangement: Two leaves at a node, one on the opposite side of the stem from the other. See Figure 19.
opposite Figure 19.

 

Oval Leaf Shape: Broadly elliptical, with the width usually greater than one half of the length. See Figure 20 .
oval Figure 20.

 

Ovary: Basal portion of the female flower that becomes a fruit.

 

Ovate Leaf Shape: Egg-shaped, with the broadest half below the middle. See Figure 21.
ovate Figure 21.

 

Ovoid: Shaped like an egg with the attachment at the broad end.

 

P

Palmate: A pattern where the leaves or leaf veins radiate from one point (as fingers radiate from the palm of a hand).

 

Panicle:  A branched inflorescence where the bottom flowers open first. 

 

Pedicel:  The stalk of a single flower in an inflorescence.

 

Perennial: A plant which lasts for three or more years.

 

Petal: One of the individual parts of the corolla.

 

Petiole: Stalk supporting the leaf.

 

Pinnate:  Arranged like a feather. In venation, major veins extend from the midrib to the margin. See Figure 21b .
oval Figure 21b.

 

Pinnately compound: A compound leaf divided into leaflets arranged on opposite sides of the stem.

 

Pit: The stone of a fruit such as in a plum or cherry.

 

Pith: Soft, spongy tissue in the center of the stem or roots.

 

Pods: Dry fruit that opens when mature.

 

Pome Fruit Type:  A fleshy fruit having seed chambers and an outer fleshy part. Ex: apple and pear. See Figure 22.
pome Figure 22.

 

Prickles:  A small, spine-like growth.

 

Pubescent: Covered with short, soft hairs.

 

Pyramidal:  Shaped like a pyramid, with a broad base and tapered point.

 

R

Raceme Flower Arrangement: An inflorescence consisting of a central stem bearing a number of pedicelled flowers; the pedicels of nearly equal length. See Figure 23.
raceme Figure 23.

 

Receptacle: The enlarged upper end of the stalk of a flowering plant, on which the flower parts are held.

 

Revolute Leaf Margin: Rolled backward, or underneath. See Figure 24.
fgh Figure 24.

 

Rhizome: Any prostrate, elongated, stem growing partially or completely beneath the surface of the ground.

 

Rosette Leaf Arrangement: Arrangement of leaves radiating from a crown or center and usually growing close to the ground. See Figure 25.
ghj Figure 25.