Observations on Lycopersicon spp.
a. Desert area: The only species common in this area seems to be L. pimpinellifolium found in the
usual situation: irrigation ditches, cultivated lands, or in the rainy years in areas along the fences
intermingled with the natural desert vegetation that springs up in the area during such years (e.g. 1972).
There is a 1972 collection of L. peruvianum (DHUNA 1080) from near the coast. This is the northernmost
site for this species.
b. Mountain zone: This zone is typical of any Peruvian valley of the northern region having a little
more moisture than the southern part. A few populations of L. hirsutum have been reported in this area.
Forma glabratum possibly reaches its southern limits here, although none of the accessions that we have
grown conform well with Muller's (1940) concept. The altitude range for this species is between
approximately 900 and 2500 m. Two collections, La Filadera (1966) and Clark (1974), are of doubtful
determination, as glandulosum and peruvianum are the denominations used by the collectors,
respectively.
Collections in the Piura valley are meager. It is included in the Chira-Tumbes-Puyango complex
which has rarely been visited "taxonomically" and which should produce some valuable material since
the change in climatic, altitudinal, and ecological relations into typical Ecuadorean and tropical
conditions finds its transition zone here This area is also important for understanding the position of
material in the Marañon drainage. Three possible connections exist between the latter and the coast: 1)
Olmos-Jaen (Abra Porculla), 2) San Juan-Cajamarca (Abra Gavilán), and 3) Chiquian-Huanuco.
The amount of L. pimpinellifolium in the lower and middle Piura basin, Sechura desert, and Pampa
de Olmos is probably the largest known, since it covers about 15,000 square kms. There are collections
from each of these vast surfaces but the definite plans for disturbance by man through the Olmos,
Chira-Piura, and Puyango-Tumbes irrigation projects makes the need for collecting urgent, especially
since it can be done only in one of those "rare" years when the desert region gets sufficient moisture for
good seed germination and development of flowers and fruits.
2. Watersheds in the Lambayeque area: Olmos, L a Leche, Chancay, Reque and Sana
(Table 6, fig. 2, 3)
The Olmos is loosely separated from the Piura watershed by the Naupe mountains (altitude not more
than 500 m) and meets the Huancabamba-Marañon eastern drainage at the Abra de Porculla (the lowest
pass in the northern Andes of Perú). This makes the watershed separation pretty much academic from
the point of view of interchange of plant material. A detailed floristic study of the area is thus justified to
support such an interchange.
The area from Rio La Leche to Rio Reque on the other hand does form more of a unit. It is one
vegetational complex in the lower part, especially since the completion of the Tinajones irrigation project.
The upper drainages are separate, the Reque going much deeper into the Andes and having a much
larger size than the La Leche. Seasonal rains in the mountains during November through April define
the river flow modified now through the Tinajones dam at Chongoyape and the corresponding irrigation
and drainage project. The Pampas de Olmos to the north and coastal areas in the valleys have sporadic
rains in every 2 out of 5-7 years.
Predominant crops are rice and chick-peas (Cicer spp.) in rotation and sugar cane. Fruits such as
grapes, mango, avocado and miscellaneous species (mamey, ciruela (Spondia spp.) are found in home
plantings. Some cotton (cv. del Cerro) and maize are grown throughout the region.
Observations on Lycopersicon spp.
The populations of L. pimpinellifolium are abundant especially from Mochumi north; the other
species have been collected rarely.
Worthy of mention is L. hirsutum of Abra de Porculla and Hda. Carrizal (between Chongoyape and
Llama). These populations should be collected again and studied in terms of their relationship to those
of the Ecuadorian and Marañon basins. The migration possibilities here are real due to the above
mentioned low altitude of the Andes at this point. In addition,
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