Horticulture 202 Laboratory 3

How to Write a Scientific Name

Practice Writing a Scientific Name

What is a Key?

Rules For Using a Key

Sample Key

Key Tutorial

Horticultural Sites
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
Online Key Tutorial
Instructions
  • Read both statements in each couplet.  The couplets are color coded for clarity.
  • Select the statement you feel is correct, and click on the number or plant name that follows that statement. 
  • A new window will appear to tell you if you were correct or incorrect.   Re-size the new window to view concurrent with the Key, or close the window between selections.
  • The correct selection will send you to another numbered couplet.
  • Continue until the correct plant name is obtained.
Try "keying out" this Sansevieria
Key out this plant!

1) Plant with evident upright stem, leaves arising along entire length . . . . . . . . 

 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  .S. powellii
1) Plant without evident upright stem, leaves arising from basal clusters . . . .(2)

2) Mature leaves cylindrical, and channeled only on younger or basal clusters. .

. . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . .S. cylindrica
2) Mature leaves flattened and expanded, much wider than thick . . . . . . . .. .(3)

3) Leaves not variegated or with light and dark green transverse bands on

younger growth and becoming obliterated with age . . . . . . . . . . . .. . . . . (4)
3) Leaves conspicuously variegated with transverse or linear striations . . .  . (7)

4) Leaves dark green, never banded . . . . . . . . . . . . . . . . . . . . . .S. nelsonii
4) Leaves with light and dark green transverse bands on younger growth

and becoming obliterated with age . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .(5)


5) Leaves broad with a thin brownish-white margin and rosette-like to

  semi-erect type growth . . . . . .. . . . . . . . . . . . . . . . . . . . . . .S. subspicata
5) Leaves upright, linear and much longer than wide, without brownish-white
margin . . . . . . .  . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . .(6)


6) Leaves 3-4 per growth, 1 1/16 to 2 1/2 inch broad, upper surface entirely
    dark green, or on younger leaves indistinctly transversely banded and

under-surface paler with bands . . . . . . . .. . . . . . . .  . . . . . . .S. liberiensis
6) Leaves 6-14 per growth, 1/3 to 1/6 inch broad, younger growth more
   distinctly horizontally banded with equally distributed bands on both 
surfaces . . . . .  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .S. parva


7) Plant with basal or rosette type growth, rarely over 6-8 inches tall, leaves 

not more than 2-3 times longer than wide  . . . . . . . . . . . . . . . . . . . . . . .. .(8)
7) Plant with ascending growth; leaves many times longer than wide . . . . . .(10)

8) Leaves green with yellow linear striations . . . . . . . . . . . . . . . . . . . . . . . . . 

. . . . . . . . . . . . . .  . . . . . . . . . .. . . .S. trifasciata cv. Golden Hahnii
8) Leaves entirely light or dark green .  . . . . . . . . . . . . . . . . . . . . . . . . . . . ..(9)

9) Leaves predominantly dark green with pale green transverse bands . . . . . .

. . . . . . . .  . . . . . . . . . . . . . . . . . . . . . . . . . . .S. trifasciata cv. Hahnii
9) Leaves with much less dark green, mostly pale green cross-bands to give 
leaf a metallic ash-green to silvery color, leaves narrower and more erect .  . . 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .S. trifasciata cv. Silver Hahnii


10) Leaves dark green with light green transverse bands, with distinct 

longitudinal golden-yellow stripes along margin . . . . . . . . . . . . . . . . . . . . . . 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .S. trifasciata var. Laurentii
10) Leaves without yellow variegation . . . . . . . . . . . . . . . . . . . . . . . . . .(11)

11) Leaves only transversely banded with light dull green and deep grass-green

bands . . . . . . . . . . . . . . . . . . . . . . . . . . . .  . . . . . . . . . . . .S. trifasciata
11) Leaves in part transversely banded with light and dark green, also linearly
striated with whitish to light green striations . . . . . . . . . . .  . . .  .S. liberica
Source of Key: D. W. Reed. 1978. Sansevieria--Identification and Culture. Louisiana Society of Horticultural Research 14(2):30-77.

| Home | Hort 202 (Lab) | Hort 201 (Lecture) | Aggie Horticulture | Texas A&M University |


This site was created by Michelle Meche and is maintained by David Wm. Reed. 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 M. Meche, TAMU.