Fabaceae: Pea Family — Lathyrus (Pea)

The pea family has 5-petaled flowers, consisting of a wide upper banner petal, two wing petals, plus two lower petals which are fused to form a boat-shaped keel.  Many genera have flowers in heads or spikes, comprising many individual flowers.  Examples are lupines and clovers.  The seed pod is generally a “legume”.  This is a long, flattish pod, swollen by the seeds, and splitting lengthwise along both the top and bottom.

Angled Pea – Lathyrus angulatus

Blooms:

Apr–June

Plant Height:

20–30 cm

Flower Size:

Small

Origin:

Europe

Habitat:

Disturbed places

Notes:

This is a glabrous annual, distinguished by its single lavender or purple flower.  The flower is near the top of the stem, which continues beyond the flower as a sharp bristle.  Leaves have 2 leaflets, 2–6 cm long, threadlike to narrowly lanceolate.  Fruits are glabrous, about 2 x the length of the flower.

Caley Pea – Lathyrus hirsutus

Blooms:

May–Aug

Plant Height:

1–3 m

Flower Size:

Small

Origin:

Eurasia

Habitat:

Disturbed or wet places

Notes:

The flowers of Caley Pea are similar to Angled Pea (Lathyrus angulatus, see above).  However, it has 1–2 flowers, pink, blue or bicolored, on a winged stem which does not extend beyond the flower.  Leaves have 2 narrow leaflets, 3–6 cm long.  Fruits have hairs with bulbous bases.  Often cultivated, uncommon in the wild.

Silky Beach Pea – Lathyrus littoralis

Blooms:

Apr–June

Plant Height:

10–60 cm

Flower Size:

Medium

Origin:

Native

Habitat:

Coastal dunes

Notes:

This low-growing plant is distinguished by its habitat (strictly coastal dunes), and by the silvery, silky appearance of its small leaflets.  Unlike Common Pacific Pea (Lathyrus vestitus, see below), it has only 4–8 leaflets, and the leaf ends in a short, bristle-like tendril.  Flowers are white to purple.

Tangier Pea – Lathyrus tingitanus

Blooms:

Apr–July

Plant Height:

< 2 m

Flower Size:

Large

Origin:

Mediterranean

Habitat:

Escape from cultivation, coastal areas

Notes:

This a sprawling or climbing plant with a prominently winged stem and 1–3 large crimson to maroon flowers. Leaves have 2 leaflets, 2–6 cm, lanceolate to widely ovate.  Often cultivated, occasionally found in the wild.

Common Pacific Pea – Lathyrus vestitus var. vestitus

Blooms:

Feb–June

Plant Height:

Climbing

Flower Size:

Medium

Origin:

Native

Habitat:

Woodland, chaparral margins, roadsides

Notes:

This is a common climbing or sprawling plant, with clusters of pale lavender to purplish flowers.  After the older flowers wither, they turn brownish but remain on the stem.  Leaves have 8–16 leaflets,  linear to elliptic.  Note the unusual style, flattened with hairs concentrate on one side of the tip like a miniature toothbrush.  Note also the simple stipules.  The style and the stipules help distinguish this species from the not dissimilar American Vetch (Vicia americana).