398 
The Ohio Naturalist. 
[Vol. XV, No. 2, 
Key to the Species. 
1. Leaflets 1 pair. 2. 
1. Leaflets 2-6 pairs. 3. 
2. Stems wingless, flowers yellow. Lathyrus pratensis. (6). 
2. Stems winged, flowers usually purple to white. 4. 
3. Flowers purple. 5. 
3. Flowers yellowish-white. Lathyrus ochroleucus. (5). 
4. Stems broadly winged glabrous, perennial. Lathyrus latifolius. (7). 
4. Stems narrowly winged, annual Lathyrus odoratus. (8). 
5. Stipules broad, foliaceous, regularly halberd shaped, leaflets ovate. 
Lathyrus maritimus . (1). 
5. Stipules narrow, half sagittate or wanting leaflets obovate. 6. 
6. Inflorescence with 10-20 flowers. Lathyrus venosus. (2). 
6. Inflorescence with 2-6 flowers. 7. 
7. Leaflets linear or linear oblong, stems winged. Lathyrus palustris. (3). 
7. Leaflets oblong or oval, stems wingless. Lathyrus myrtifolius. (4). 
1. Lathyrus maritimus (L) Bigel. Beach Pea. A glabrous 
climbing or erect perennial with a grooved angled stem, 1-2 ft. 
high and % in. in diameter. Leaflets 2-6 pairs, oval, 1 % in. long, 
1 in. wide, tendrils branched, stipules broad, foliaceous, and 
regularly halberd shaped. Peduncle shorter than the leaves; 
flowers 6-10, racemose, purple, %-l in. long; pod glabrous, l%-3 in. 
long, %-% in. wide, seeds 3-10, light brown. 
Ashtabula, Lake, Cuyahoga and Erie. It is also called 
Sea-pea, Sea-side-pea and Everlasting-pea. 
2. Lathyrus venosus Muhl. Veiny Pea. A trailing or 
climbing glabrous, or finely pubescent perennial, with a 4-angled 
stem, 2-3 ft. long and % in. in diameter. Leaflets 2-6 pairs, 
obovate, 1-2 in. long, %-1 in. wide; tendrils compound, stipules 
narrow, half sagittate or wanting. Peduncles shorter than the 
leaves; flowers 10-20, %-% in. long, purple; pod linear, 1-3 in. long, 
in. wide; seeds 3-8, brown. 
The Veiny Pea usually grows near rivers or lakes. Erie and 
Williams. 
3. Lathyrus palustris L. Marsh Pea. A climbing, slightly 
pubescent or glabrous perennial with an angled, usually winged 
stem, 1-3 ft. long and % 6 in. in diameter. Leaflets 2-6 pairs, 
linear or linear oblong, 1-2/4 in. long, %-% in. wide; tendrils 
branched, stipules narrow, half sagittate or wanting. Flowers 
2-6, % in. long, purple; pod linear, 2-2% in. long, %-% in. wide, 
the seeds 3-6, brown. 
The Marsh Pea is found in moist or wet soil. Lake, Cuyahoga, 
Summit, Erie, Madison and Greene. It is also called Wild Pea. 
4. Lathyrus myrtifolius Muhl. Myrtle-leaf Marsh Pea. A 
slender climbing, glabrous, or slightly pubescent perennial, with a 
wingless, angled stem, 1-3 ft. long, and %6 in. in diameter. Leaflets 
2-6 pairs, oblong or oval, 1-2 in. long, %-% in. wide; tendrils 
branched; stipules %-% in. long, narrow, half sagittate or wanting. 
Flowers 2-6, purple, %-% in. long; pod linear, 2 in. long, % 6 in. 
wide, the seeds 3-8, brown. 
This species is found in moist or wet localities. Lake, Stark, 
Erie, Lucas, Defiance and Auglaize. 
