"Uncle Derek Says"

Ecuadorian Platyaechmea

Derek Butcher " These are very popular plants and include the likes of Aechmea chantinii, Aechmea zebrina, Aechmea tessmannii and Aechmea retusa and to the casual observer look very similar. They certainly need similar growing conditions that Adelaide cannot supply, so all I can do is admire them from a distance!
Identification is not that simple and for some reason Aechmea zebrina has been confused with Aechmea chantinii. So no doubt there are other misidentifications and I thought a good way to tackle the problem would be to show two ways of looking at this group using different Keys.
One is based on Lyman B. Smith's Key and the other by Harry Luther is the one with the photographs. Usually with Keys you do not get photographs, so we will be different!
Some of the criteria in the Keys are visible in the photographs to help you decide what the correct name is on your plant.
To complete the set we are seeking photographs of Aechmea tillandsioides. "

Platyaechmea Key for Ecuador

based on L B Smith's concept

1.	Sepals exserted beyond the bracts at anthesis	2
	Sepals included in the floral bracts at anthesis	3
2.	Floral bracts elliptic, cucullate, much exceeding ovary, leaf blades concolorous	*manzanaresiana*
	Floral bracts elliptic, retuse, much exceeding ovary, leaf blades concolorous	*retusa*
	Floral bracts broadly ovate, sub-truncate, slightly exceeding the ovary, leaf blades usually conspicuously white banded	*chantinii*
3.	Leaf blades broadly white banded beneath, floral bracts to 28mm long	*zebrina*
	Leaf blades concolorous, floral bracts to 25mm long	4
4.	Spikes sessile, sepals sub-free	*tillandsioides*
	Spikes with peduncles	5
5.	Primary bracts (large flags below the spikes) abruptly smaller, sepals asymmetric and oblong	*moorei*
	Primary bracts diminishing gradually	6
6.	Floral bracts leathery, not particularly nerved, narrow and exposing the rhachis at anthesis	*tessmannii*
	Floral bracts leathery, thin nerved, large and cucullate (hooded)	*cucullata*
	Floral bracts papery, prominently nerved, ample and covering rhachis at anthesis	*romeroi*

Platyaechmea Key for Ecuador

by Harry Luther

1.					Branches of inflorescence sessile	*tillandsioides*
1.					Branches of inflorescence pedunculate
	2.				Primary bracts abruptly reduced in size toward the apex of the inflorescence
		3.			Floral bracts only slightly exceeding the ovary in length	*chantinii*
		3.			Floral bracts much exceeding the ovary in length, about 1/2 as long as the sepals	*moorei*
	2.				Primary bracts gradually reduced in size toward the apex of the inflorescence
		4.			Spike rachis broad, 4 - 7mm wide, excavated
			5.		Sepals asymmetrical
				6.	Floral bracts 12 - 20mm long, the apex straight; sepals 10 - 14mm long	*retusa*
				6.	Floral bracts 23 - 30mm long, the apex cucullate; sepals 16 - 20mm long	*cucullata*
			5.		Sepals symmetrical
				7.	Sepals 13 - 15mm long, exceeded by to slightly exceeding the floral bracts	*tessmannii*
				7.	Sepals 15 - 18mm long, much exceeding the floral bracts	*manzanaresiana*
		4.			Spike rachis narrow, 2 - 3mm wide, angled but not excavated
				8.	Leaves conspicuously banded; floral bracts 25 - 30mm long	*zebrina*
				8.	Leaves not banded, floral bracts 23 - 25mm long	*romeroi*

It should be noted that sympatric species of Aechmea subgenus Platyaechmea in Amazonia appear to hybridise occasionally, making identification of some specimens problematic, if not impossible.

Click on the thumbnails to view the pictures.
Send your comments and opinions to UncleDerekSays@fcbs.org
Your comments will be added to this page.

6-27-99
A comment from Geoff Johnson, Pineapple Place, Longwood,FL:
A short comment about the Platyaechmeas.
They are notoriously promiscuous. In my collection they stand cheek by jowl and are constantly producing seed which grow into fascinating and sometimes grotesque offspring. I have been careful to label the progeny Platyaechmea hyb. unk. but I'm sure I have contributed to confusion in this complex by propagation and promulgation of these plants.

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Photo Credits:
Aechmea chantinii - Michael Andreas
Aechmea chantinii flower - John Catlan
Aechmea moorei - BSIJ 1970 p176
Aechmea retusa and flower - John Catlan
Aechmea cucullata - John Catlan
Aechmea tessmannii and flower - Peter Franklin
Aechmea tessmannii, two other forms - Jarka Rehak
Aechmea zebrina - Peter Tristram
Aechmea zebrina - Peter Franklin
Aechmea romeroi - Peter Tristram
Aechmea romeroi flower - John Catlan
Aechmea manzanaresiana - Peter Tristram

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