2. The Chicama and nearby lomas. Despite the small number of collections, this region is distinctive
in two features -- the endemic ecological conditions of the Cascas-Contumazá area and the only
loma collections known for the species.
3. The Moche-Pisco region. Here three gaps can be detected in collections: one between the Moche
and the Santa, another between the Casma and the Fortaleza, and the third between the Lurín
and the Canete. The reasons for the gaps seem to be: (a) the rivers do not have enough moisture
to sustain growth at the altitude preferred by the species; (b) they have not been explored
sufficiently in favorable years; and (c) the populations are usually very small.
4. The Marañon region. East of the Andean divide, only the Marañon River and its tributaries have
yielded hirsutum accessions. We have arbitrarily divided the collections into two subgroups: (a)
the collections of the Huancabamba and Cajamarca Rivers, which are closely related to those of
the Piura and Jequetepeque watersheds, respectively; and (b) specimens from tributaries that
flow directly into the Marañon. Identification of the latter group is of doubtful reliability because
the locations are isolated and scattered and because no seed is available to permit the growing of
test cultures. The situation should be cleared up by a collecting expedition into this highly
complicated and poorly understood vegetational area.
f. glabratum extends southward from Ecuador to Olmos (6o south latitude) in the Chira-Jequetepeque
region and is found from 500 to 2700 m. The fruit seems to be available in the last part of winter and
early spring (Aug.-Oct.), and plants spread along hillsides in the usual quebrada situations in the
presence of abundant shrubby vegetation. In the Chancay-Jequetepeque area, conditions are drier,
vegetation is sparse, and f. typicum starts to appear.
b. L. chilense (Table 2). This species is present in the exceedingly arid region of southern Perú from
Chaparra to Tacna and along the northern coast of Chile. Populations are tiny north of Moquegua,
but southward they tend to be larger. Seed collections were made in the November through April
season which corresponds to the "rainy season" in normal years. Since this period is too short for
vegetative growth (from the perennial "stumps"), flowering, and seed production, the collection of a
good seed supply in a given year indicated that sufficient moisture was received in the previous year.
In fact, mature fruits have been collected two years after the last recorded rainfall.
The altitude ranges can be roughly divided into three levels: (1) sea level to 1800 m; (2) 2200-
2500; and (3) 2800-3000. Good data for vegetation associations are not available; one good reason is
that several sites have been described as extremely dry desert situations where very few other plants
survive. One sympatry reported is with L. peruvianum in lomas of Tambo at 500 to 1300 m and
another with yellow-flowered Solanum lycopersicoides at Palca, Caplina watershed, 2500 m.
The sites are very dry and stony with sandy situations in washes (quebradas) for half of the
collections; and for the other half, they are roadsides (500, 1000-1500, and 2900 m) or hillsides
(1000-1400, and 3000 m).
c. L. peruvianum (Table 3). In the overall analysis of collectors' data, this species is divided into four
geographic categories: (1) the loma collections, (2) the region from Ecuador to the Reque-Chancay
watersheds, (3) the coastal type and the "mountain races" from the Jequetepeque to the Nazca Rivers,
and (4) the area of peruvianum/chilense sympatry from Rio Lomas to northern Chile. These
apparently natural divisions are based mainly on the data reviewed and the crossability relations
developed by Rick (1963; summary in his fig. 4).
L. peruvianum has been collected since 1788 (Ruiz and Pavón, Rímac watershed) and is still found
today in old and new sites. It is rare north of the Jequetepeque and has not been collected in such
short valleys as Virú, Chao, Nepeña, and in a gap between the Pisco and Nazca drainages. In
southern Perú it gradually disappears as L. chilense completely replaces it in the Moquegua, Sama,
and Caplina watersheds. In northernmost Chile (Arica) both species are found; southward only L.
chilense has been reported.
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