Monographs Details: Lotus argophyllus var. argophyllus
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.
Description:Distribution and Ecology - Range as given in key, and Baja California. S Sierra foothills, s to San Diego co, slightly in coastal ranges in Monterey and San Luis Obispo cos. Dry slopes, canyon washes, common with lower Sonoran chaparral. 500-4000(-7000) ft. March-July.
Discussion:Hosackia argophylla Gray (1954); Syrmatium argophyllus (Gray) Greene (1887); Lotus argophyllus (Gray) Greene (1890).
H. argéntea Kellogg (1863).
H. argophylla var decora I. Jonst. (1918); L. argophyllus var decorus (I. Johnst.) Ottley (1923).
Except in the Transverse Ranges, Lotus argophyllus var argophyllus is reasonably distinctive. Northward, it is intergradient with var fremontii in the middle Sierra Nevada, and in the coastal ranges of Monterey co. Southern California populations are commonly more pubescent and perhaps have smaller flowers than those of the Sierra Nevada. One specimen (possibly a hybrid derivative) of Tulare co has the curved pubescence of L. nevadensis but the pods are not exserted.
In the Transverse Ranges (San Gabriel to San Bernardino Mts.), Lotus argophyllus var argophyllus is racially diverse. Variation in flower size, proportionate length of calyx teeth, level and nature of the pubescence, length of the peduncles, and degree of exsertion of the pods renders interpretations subjective, resulting in identifications of these plants as L. argophyllus, L. argophyllus var decorus, L. nevadensis, L. douglasii, L. davidsonii, and even L. heermannii. Perhaps introgression between L. argophyllus and L. nevadensis is a cause of this diversity. Or, possibly L. argophyllus var argophyllus includes several subspecific taxa that I do not have sufficient information to evaluate. The most distinct types are:
/. Umbels pedunculate, 1-2 cm; flowers large, 8-10 mm; pubescence deeply silvery to thin; hairs straight to somewhat flexuous; degree of exsertion of pod not evident from available specimens; San Gabriel to San Bernardino Mts., n to ne Kern co. Ca. 2500-4800 ft.
2. Umbels sessile; flowers smaller, 7-8 mm; pubescence velutinous; legume strongly exserted, San Gabriel and San Antonio Mts. Ca. 1000-4000 ft. This is the original Hosackia argophylla var decorus I. Johnst. but not Lotus argophyllus var decorus of Munz (1959), an upper elevation form with strongly pedunculate umbels, that I refer to L. nevadensis.
3. Umbels sessile, densely compact with numerous, small flowers 7-8 mm; pubescence velutinous; legume, as to material seen, little exserted. San Bernardino Mts.; 7-4000-4500-? Sensu characters, these seem to be typical Lotus argophyllus.
Distribution:United States of America North America