Lotus heermannii (Durand & Hilg.) Greene

Authority

Isely, Duane. 1981. Leguminosae of the United States. III. Subfamily Papilionoideae: tribes Sophoreae, Podalyrieae, Loteae. Mem. New York Bot. Gard. 25 (3): 1-264.

Family

Fabaceae

Scientific Name

Lotus heermannii (Durand & Hilg.) Greene

Description

Species Description - Mat-forming, often precociously flowering, villous or thinly strigose perennial with clustered, prostrate stems 3-10 dm. Young growth conspicuously villous with hairs ca. 1 mm, but stems often glabrate at maturity. Leafstalk 2-10 mm, somewhat flattened; leaflets ovate to obovate, 4-16 mm, 1.8-2.5 r. Stipules reduced to glands. Umbels subsessile to usually peduncled, 1—4(—5) mm, with 3-8 flowers 4-6(-7) mm, distally bracteate. Calyx tube 1.5-3 mm, usually villous; teeth .5-1.5 mm. Corolla yellow to reddish and dark-tipped, irregularly graduated; keel subporrect. Ovary pubescent with 2-3 ovules; style geniculate 90° or incurved, rapidly elongating. Pods ascending or divergent, exserted, nearly straight to usually strongly arcuate, abruptly beaked, indehiscent and deciduous with calyx; valves pubescent. Seeds 1-2. Syrmatium.

Discussion

This small-flowered perennial may have the aspect of the inland Lotus neva-densis var nevadensis or of the coastal L. junceus, and is sometimes identified as L. argophyllus var decorus (or vice versa). It is usually easily distinguished from these species by its villous, new growth and usually smaller flowers. It has been alleged (Ottley, 1923), and reiterated (Munz, 1959) that the interior forms are more quickly glabrate and have smaller flowers than those of the coast, on which basis Ottley recognized two varieties. Her position was somewhat supported by Hoover (1970) who observed that the villous, coastal types tend to have the longer calyx lobes. The coastal forms, indeed, on the average, are more evidently or persistently pubescent, but this feature is too variable to be diagnostically critical. Probably Jepson (1936), who recognized no subspecific categories, held the same view. Lotus heermannii, however, falls into two discrete geographic units, of which the northern averages the more pubescent. These elements constitute weak varieties because some specimens cannot be identified independently of origin. The division is useful in that there is some morphological correlation with dispersal, and is theoretically reasonable because coastal plants in San Diego co probably have a closer genetic relationship to those of the contiguous interior than with coastal populations of Monterey co.

Distribution

Cismontane California and Baja California. San Diego to Sonoma cos, primarily coastal cos but inland w of desert in s California. Said to be cult.

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