Jaltomata (Solanaceae) of the lomas formations of Peru
by Thomas Mione and Segundo Leiva G.
Link to Jaltomata home page
The information on this page may be cited as a communication with professor Thomas Mione, Central Connecticut State University, Biology Department, Copernicus Hall, 1615 Stanley Street, New Britain, CT 06050-4010. This page was updated in March of 2008.
Literature Cited

Lomas formations are highly endemic plant communities occurring in near-shore locations of Peru and Chile where ocean fog provides sufficient moisture for the development of vegetation (nearly verbatim from Dillon 2005). "Each locality is an island of vegetation among a virtual ocean of arid desert, ..." (Dillon 2005). In the genus Jaltomata there are at least five species that grow in this habitat.

Biogeography: The Jaltomata species of the lomas (see the table below) are not a monophyletic group. In general, the closest relatives of these species are Andean members of this genus. Jaltomata lomana, J. hunzikeri, a new species not yet described from Cerro Campana (J. "truxillana"), and a new species from Arequipa are endemic to lomas and known from a single locality. Jaltomata lomana is rare and hard to find on the one small coastal mountain on which it grows. Segundo Leiva, Leon Yacher and I searched for J. hunzikeri at its type locality and we could not find it, despite the fact that we are otherwise always successful at finding plants of this genus at any locality at which they have been found in the past. Jaltomata "truxillana" is endemic to Cerro Campana, a small isolated, near-shore mountain, and fewer than 40 plants exist. Jaltomata umbellata and J. aspera appear not to be in imminent danger of extinction. Jaltomata aspera is the only member of the genus growing both in the Andes and in the lomas, with plants of the Andes flowering at a different time of the year than the plants of the lomas.

These six Jaltomata species grow in small islands of suitable habitat (lomas) from northern Peru to Southern Peru. More specifically, these species range from Department La Libertad at about 8 degrees South lat. to Department Arequipa at about 16 degrees South lat., a span of roughly 888 km. North to south, the first two species, J. "truxillana" and J. lomana, are about 189 km away from each other. And from J. lomana to J. hunzikeri is another approximately 222 km. Thus, the Jaltomata species of the lomas are widely separated from each other, and are generally closer to the Andes than to each other. Jaltomata umbellata and J. aspera are an exception: These two species grow in the same region and have even been collected in the same lomas formation (Amancaes). Interestingly, these two species seem the least likely to compete for pollinators because J. umbellata has a tubular corolla and J. aspera has a satellite-dish shaped corolla.

What is the explanation for this geographic distribution? There are two non-mutually exclusive possibilities: 1) Separate dispersal events from (or to) the Andes, with new populations being small and therefore subject to genetic drift/bottlenecks, and likely subjected to selection by new pollinators and new abiotic factors. 2) Vicariance is another possible explanation. In other words, perhaps there was more widespread suitable habitat for Jaltomata in the past, and gradual and fluctuating drying separated the few coastal habitats (lomas) from the higher Andes that are still suitable for growth of the genus. As mentioned, J. aspera grows both in the lomas and in the Andes, and at present we do not have data that shows whether the high altitude plants are ancestral to the lomas plants, if the lomas plants are ancestral to the high altitude plants, or if the lomas and the high altitude plants are the remnants of a once wider distribution for this species.


In the following table the Jaltomata of the Peruvian lomas are listed (left to right) from north to south.

 

"truxillana" sp. of Cerro Campana
lomana
hunzikeri
umbellata
aspera
unpublished name
"ArequipaPurple"
 
Department
La Libertad
Ancash
Lima
Lima
Lima
Arequipa, prov. Caraveli
habit
shrub
shrub
shrub
shrub
herbaceous, or herbaceous and woody only at base
described as "annual" on specimen so must have been herbaceous
Months in flower
August - October
September, January
September
July - October, January
September - October in lomas; January, March, April in Andes
October
endemic to lomas?
yes
yes
yes
yes
no
seems to be
Known from a single locality?
yes
yes
yes
no
no
seems to be
deciduous leaves
yes
had leaves in January (Mione, Leiva & Yacher 631)
no data
no
no data
no data

Islands: All of the above species may be viewed as growing on virtual islands. Two additional Jaltomata species grow on oceanic islands, J. antillana (Greater Antilles) and J. werffii (Galápagos Islands).

Deciduous: Jaltomata "truxillana" (Cerro Campana, Department La Libertad) is deciduous, dropping its leaves for the dry season. Jaltomata umbellata appears not to be deciduous: I visited a population at Reserva Nacional de Lachay in June of 2005 during a drought and J. umbellata plants had leaves! Whether or not the other species are deciduous is unknown.

Red-Orange Nectar: Jaltomata aspera, J. umbellata and the species known for now as "ArequipaPurple" produce red-orange nectar.
Click here for a table of Jaltomata species having red to orange nectar.

Endemism: At least four of the six species are endemic to the lomas; see table for details.

Which Months Are These Species In Flower?: In the lomas, all of these species bloom in September/October. See above table for clarification and details.


Key to the Jaltomata of the Peruvian lomas formations:

1. Herbaceous but perhaps woody at base; Corolla broadly campanulate (not tubular), nectar red . . 2

1. Shrubs; Corolla short-tubular with a limb, green to white, nectar clear or red . . . . . . . . . . . . . . . 3

2. Having 10 green corolla maculae, the corolla purple . . . . . . . . . . . . . . . . . . . . unpublished J. "ArequipaPurple"

2. Lacking corolla maculae, the corolla green-yellow or yellow-green . . . J. aspera

3. Corolla tube at least 6.5 mm long and containing red nectar . . . . . . . . . . . . . . . J. umbellata

3. Tubular part of the corolla less than 6.5 mm long, lacking red nectar . . . . . . . . . . . . . . . . . . 4

4. Corolla with blue ring in tube; young axes, petioles, peduncles, pedicels, and abaxial face of calyx villous J. hunzikeri

4. Corolla tube lacking blue ring; axes and leaves glabrous or nearly so . . . . . . . . . . . . . . . . . . . . . . 5

5. Corolla white, the limb spreading (not planar); stamens included . . . . . . . . . . . . . . . J. lomana

5. Corolla limb lavender near tube, fading to white toward margin of limb, the limb planar; stamens exserted . . . . . unpublished J. "truxillana"


Acknowledgements: Gregory J. Anderson and Gabriel Bernardello provided the environment conducive to the birth of this project. Michael Dillon has provided valuable information about the lomas habitat, in correspondence, copies of his published work and in presentations at meetings. I thank Arturo Granda and Graciela Vilcapoma for sending me herbarium specimens and the photo of J. aspera shown above. Arturo Granda was the first botanist to bring the Arequipa specimen (last column of table) to my attention, in 2001. Segundo Leiva illustrated J. lomana (shown in the table above) and took the photo of J. "truxillana" shown above. Rene Chavez sent to Tilton Davis IV seeds of J. umbellata and T. Davis generously passed the seeds on to me.