Wildflowers Blooming in Pennsylvania in September (60 Species)

60 wildflowers were recorded blooming in Pennsylvania in September in our iNaturalist sample; 25 of the top 50 are at their peak this month. The list is ranked by number of research-grade observations.

Feb Mar Apr May Jun Jul Aug Sep Oct Nov

Top wildflowers in September

White Snakeroot717 obs.

Common Jewelweed468 obs.

Great Blue Lobelia239 obs.

Wingstem234 obs.

Flat-Topped Goldenrod204 obs.

Bluestem Goldenrod161 obs.

Asiatic dayflower153 obs.

New England aster153 obs.

Chicory147 obs.

Tall Goldenrod137 obs.

American hog-peanut134 obs.

brown-eyed Susan132 obs.

All wildflowers blooming in Pennsylvania in September

#	Species	Scientific name	Family	Obs.	Peak in state
1	White Snakeroot	Ageratina altissima	Sunflowers, Daisies, Asters, and Allies	717	Sep (peak)
2	Common Jewelweed	Impatiens capensis	balsam family	468	Sep (peak)
3	Great Blue Lobelia	Lobelia siphilitica	bellflower family	239	Sep (peak)
4	Wingstem	Verbesina alternifolia	Sunflowers, Daisies, Asters, and Allies	234	Sep (peak)
5	Flat-Topped Goldenrod	Euthamia graminifolia	Sunflowers, Daisies, Asters, and Allies	204	Sep (peak)
6	Bluestem Goldenrod	Solidago caesia	Sunflowers, Daisies, Asters, and Allies	161	Sep (peak)
7	Asiatic dayflower	Commelina communis	Spiderworts	153	Aug (past peak)
8	New England aster	Symphyotrichum novae-angliae	Sunflowers, Daisies, Asters, and Allies	153	Sep (peak)
9	Chicory	Cichorium intybus	Sunflowers, Daisies, Asters, and Allies	147	Jul (past peak)
10	Tall Goldenrod	Solidago altissima	Sunflowers, Daisies, Asters, and Allies	137	Sep (peak)
11	American hog-peanut	Amphicarpaea bracteata	Legumes	134	Aug (past peak)
12	brown-eyed Susan	Rudbeckia triloba	Sunflowers, Daisies, Asters, and Allies	132	Sep (peak)
13	black-eyed Susan	Rudbeckia hirta	Sunflowers, Daisies, Asters, and Allies	129	Jul (past peak)
14	Pale Jewelweed	Impatiens pallida	balsam family	127	Sep (peak)
15	White Wood Aster	Eurybia divaricata	Sunflowers, Daisies, Asters, and Allies	113	Sep (peak)
16	Wild Carrot	Daucus carota	carrot family	110	Jul (past peak)
17	White Turtlehead	Chelone glabra	Plantain Family	102	Sep (peak)
18	Autumn Clematis	Clematis terniflora	buttercup family	93	Sep (peak)
19	Purple Loosestrife	Lythrum salicaria	lythrum family	88	Aug (past peak)
20	Late Boneset	Eupatorium serotinum	Sunflowers, Daisies, Asters, and Allies	87	Sep (peak)
21	Common Toadflax	Linaria vulgaris	Plantain Family	84	Jul (past peak)
22	Common Wrinkle-Leaved Goldenrod	Solidago rugosa	Sunflowers, Daisies, Asters, and Allies	84	Sep (peak)
23	Cutleaf Coneflower	Rudbeckia laciniata	Sunflowers, Daisies, Asters, and Allies	82	Aug (past peak)
24	Red Clover	Trifolium pratense	Legumes	79	Jun (past peak)
25	Blue Mistflower	Conoclinium coelestinum	Sunflowers, Daisies, Asters, and Allies	78	Sep (peak)
26	Cardinal Flower	Lobelia cardinalis	bellflower family	75	Aug (past peak)
27	Common Boneset	Eupatorium perfoliatum	Sunflowers, Daisies, Asters, and Allies	74	Aug (past peak)
28	White Clover	Trifolium repens	Legumes	71	May (past peak)
29	Silverrod	Solidago bicolor	Sunflowers, Daisies, Asters, and Allies	67	Sep (peak)
30	Purple Crownvetch	Securigera varia	Legumes	65	Jun (past peak)
31	Common Sneezeweed	Helenium autumnale	Sunflowers, Daisies, Asters, and Allies	64	Sep (peak)
32	Citronella Horse Balm	Collinsonia canadensis	Mint Family	64	Sep (peak)
33	Fall Phlox	Phlox paniculata	phlox family	63	Sep (peak)
34	Field Thistle	Cirsium discolor	Sunflowers, Daisies, Asters, and Allies	62	Sep (peak)
35	American pokeweed	Phytolacca americana	Pokeweed Family	60	Jul (past peak)
36	American burnweed	Erechtites hieraciifolius	Sunflowers, Daisies, Asters, and Allies	59	Sep (peak)
37	Trailing Fuzzy-Bean	Strophostyles helvola	Legumes	52	Aug (past peak)
38	Broad-Leaved Goldenrod	Solidago flexicaulis	Sunflowers, Daisies, Asters, and Allies	51	Sep (peak)
39	Calico Aster	Symphyotrichum lateriflorum	Sunflowers, Daisies, Asters, and Allies	50	Sep (peak)
40	Common Selfheal	Prunella vulgaris	Mint Family	48	Jul (past peak)
41	Low Smartweed	Persicaria longiseta	knotweed family	48	Oct (rising)
42	Japanese knotweed	Reynoutria japonica	knotweed family	46	Aug (past peak)
43	Bird's-Foot Trefoil	Lotus corniculatus	Legumes	43	Jun (past peak)
44	Arrow-Leaved Tearthumb	Persicaria sagittata	knotweed family	43	Sep (peak)
45	Carolina horsenettle	Solanum carolinense	nightshade family	41	Jul (past peak)
46	Indian tobacco	Lobelia inflata	bellflower family	41	Jul (past peak)
47	Wild Basil	Clinopodium vulgare	Mint Family	40	Jul (past peak)
48	Blue Curls	Trichostema dichotomum	Mint Family	40	Aug (past peak)
49	Partridge Pea	Chamaecrista fasciculata	Legumes	40	Aug (past peak)
50	Common Hibiscus	Hibiscus syriacus	Mallow and Hibiscus Family	38	Aug (past peak)