Dave Looks for Plants

Journal of a plant explorer

Posts Tagged ‘Costus laevis Podocarpus Form’

Rio Numbami

Thursday, February 19th, 2015

The next day we started out going to a nearby forested area just outside Zamora to the northwest.  There we found more of the Podocarpus form of Costus laevis at about 1100 meters, but there was not a lot of forest in the area, so we next headed for the higher altitude reserve area of Numbami Alto.

 

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In this area we found many more plants of the pubescent form of Costus laevis that we had seen at the deserted farm at Podocarpus.  This form seems to only be found at the higher altitudes (between 1200 and 1600 meters) whereas the Podocarpus form is found below 1200 meters.  The forms of the flowers and the hairiness of the leaves varies somewhat, but the plants are recognizable and distinguishable by the size of the inflorescence and the various flower parts – especially by the much smaller calyx and bracteole. 

The Podocarpus form…..

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And the pubescent form …..

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Here was a pubescent form found with pale yellow flowers.

 

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In his garden, Marco has a plant of the species Costus erythrophyllus which he collected locally many years ago, but he could not remember for sure exactly where.  Here is a photo I took of this plant during my 2007 visit in Marco’s garden – and one with flowers taken recently by Marco Jr.

 

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He thought it might have been at the nearby Quebrada Tunantza Alto, so we headed there next.  We did find a plant growing there that has purple backed leaves, but it is not the same plant as in Marco’s garden, and I don’t think it is C. erythrophyllus.  It was not in flower so I cannot say for sure but I think it more likely to be another form of C. laevis – possibly the pendent ‘El Gato’ form like the ones I saw in 2013 in Peru.

Here is the one seen at Quebrada Tunantza

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Podocarpus National Park

Wednesday, February 18th, 2015

On Wednesday we went to the Parque Nacional Podocarpus, which has a north entrance along the Rio Bombusco a short distance from Zamora.  Along the entry road we spotted a huge (literally huge) surprise.  It was the same Costus form I had seen in the park in 2007 minus flowers and here it was in full bloom.   I had collected seeds in 2007, but that plant had not yet flowered for me, so I was not sure what species it was.  The general “look” of the plant made me think Costus laevis, and here it was confirmed.  But not like any other Costus laevis form I had ever seen.  Not even close to the plants found in Central America or the western side of the Andes in South America.

Typical Costus laevis flowers from Central America

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Form found at Podocarpus National Park

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First of all, this was the biggest inflorescence I had ever seen in a Costus.  The plant itself was also fairly large and the leaves as well.  But what really caught my attention was the fact that the upper leaves were gathered around the infloresence, partially sheathing it just like the pendent flowering Costus ‘El Gato’ I had seen from nearby Gualaquiza and other places on the eastern side of the Andes. 

Later on, examining the herbarium voucher specimen of the type for the species from Peru, I can see now that the leaves are covering the inflorescence in the same way.  This all leads me to conclude that the true species Costus laevis is of the form found on the eastern side of the Andes, and the plants in Central America and west of the Andes in South America should revert back to their original species names or possibly be renamed as a separate species.  They are simply too distinctly different to be lumped into the same bucket unless there is convincing DNA evidence to the contrary.

For those who may be interested in such things, a thumbnail sheet with all the details of the flower parts can be found on my website HERE .

After we reached the park and walked along the trails we saw several more of these plants, many of them in flower, so there could be no doubt about it.

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Marco said he remembered seeing yet another plant, different from this glabrous one, having very hairy leaves.  So we kept hiking uphill and off the trail to an abandoned finca where he remembered seeing it.  After bushwhacking our way through thick brush we finally found it.  And yes, this I would is yet  another form of that diverse species we humans call Costus laevis.  To see the full details of the plant and flowers go to my THUMBNAIL SHEET for this plant.  Aside from the hairy leaves this form has much smaller inflorescence, and a very short calyx and other parts making it clearly distinct from the Podocarpus form.

 

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We walked back along the long trail that follows the east side of the river but did not see any other Costus species, except for the ubiquitous Costus scaber, that is common throughout the region. 

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We did however see one very pretty pink bracted Heliconia before heading back to Zamora.

 

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