The Pennsylvania Flora Project

Botany Department, Morris Arboretum of the University of Pennsylvania

The Pennsylvania flora includes over 3,000 kinds of plants, Abies to Zizia.

 
One third of the plants that grow in Pennsylvania today are not native to the state, that is, they were not here when the first European settlers arrived.  These plants have been brought here deliberately or by accident.  Some of them have become serious invasive weeds.
 
Many of Pennsylvania's plants are becoming increasingly hard to find in the woods because deer are voraciously consuming so much of Pennsylvania's  plant cover, especially low-growing wildflowers and shrubs.

The Pennsylvania Flora includes:

 

118 species of native trees
17 species of native oaks
57 species of native orchids
22 species of goldenrods
66 species of native ferns
322 species of grasses
170 species of Carex (sedges)

 

Major taxonomic divisions
Native
Non-native
Total
Pteridophyta
120
1
121
Pinophyta
17
12
29
Magnoliopsida
1315
1051
2366
Liliopsida
699
217
916
Totals
2151
1281
3432

Species of special concern
Number
% of native species
Federal endangered or threatened species
7
0.3%
PA extirpated
93
4.3%
PA endangered
225
10.5%
PA threatened
72
3.3%
PA rare
43
2.0%
PA vulnerable
1
<0.1%
Totals (all federal species are PA listed)
434
20.2%

Noxious weeds
Federal noxious weeds
5
PA noxious weeds
13

Largest families
Native
Non-native
Total
Asteraceae  (Aster family)
219
155
374
Poaceae  (Grass family)
180
142
322
Cyperaceae  (Sedge Family)
270
21
291
Rosaceae  (Rose family)
95
64
159

Largest genus
Native
Non-native
Total
Carex (Sedges)
170
10
180

Growth forms
Native
Non-native
Total
Deciduous trees
118
82
200
Evergreen trees
13
8
21
Deciduous shrubs
167
104
271
Evergreen shrubs
23
4
27
Woody vines
22
16
38
Perennial herbaceous vines
33
20
53
Annual herbaceous  vines
12
23
35
Annual herbs
250
521
771
Biennial herbs
39
67
106
Perennial herbs
1471
439
1910