Fabaceae: Pea Family — Astragalus (Milkvetch / Locoweed)

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.

Nuttall’s Milkvetch / Gray Locoweed – Astragalus nuttallii var. nuttallii

Blooms:

All year

Plant Height:

20–100 cm

Flower Size:

Medium cluster

Origin:

Native

Rare or Endangered?

Yes – 4.2

Habitat:

Mainly coastal, on dunes & bluffs

Notes:

Astragalus is a varied genus with many species, especially in the desert and towards the Central Valley.  Distinguishing them may require close attention to the number and color of leaflets, or to the shape and structure of the fruits, which may be inflated like a bladder.  This is the most common species found by the coast.  It has 10–21 pairs of small, oval blue-green to grayish leaflets, often in a dense tangle. Elongated clusters of creamy-white flowers develop into inflated pods, pale green below and pinkish above.  When the seeds dry, the pods rattle (hence another of its common names—”Rattleweed”)

Coastal Dunes Milkvetch – Astragalus tener var. titi

Blooms:

Mar–June

Plant Height:

2–30 cm

Flower Size:

Very small

Origin:

Native

Rare or Endangered?

Yes – 1.b1

Habitat:

Dunes and sandy flats

Notes:

Extremely rare, known only from one small area on 17 Mile Drive.  It is low-growing, with stems less than 12 cm long.  There are 2–7 tiny bluish-purple flowers in each inflorescence.  Leaves are 5–8 cm long with 7–17 leaflets.  There have been reports that the species was introduced in Point Lobos, but it is uncertain whether this is correct or, if it was, whether the plants have survived.