Related to T. imperialis according to Sue Gardner. Even more similar to T. ponderosa because of more triangular, somewhat lepidote leaves and larger overall size.
R Ehlers believes closer to T. imperialis because of size of floral bracts and sepals, and primary bracts longer than spikes.
Two High Elevation Tillandsias from Southern Mexico by Sue Gardner in J. Brom. Soc. 31(3): 123. 1981
In July, 1980 we had the opportunity to collect Tillandsia laui which was described by Dr. Eizi Matuda in Vol. XX, No. 4 of Cactaceas y Suculentas Mexicanas, (1975). Dr. Matuda compared this new species with T. imperialis Morren and described it as differing mainly in its larger size, green inflorescence and ochreous yellow flowers. While I find it indeed closely related to T. imperialis, it seems to resemble even more closely T. ponderosa L. B. Smith. It differs from T. imperialis in having more linear triangular leaves which are somewhat lepidote; a character which is shared by T. ponderosa. Tillandsia laui and T. ponderosa are also more similar in size, both being approximately twice the size of T. imperialis.
Tillansia laui is epiphytic in a moist pine and oak forest at 5,000 feet in elevation in the southern portion of the state of Oaxaca. A heavy mist was hanging in the cool air at mid-day when we collected our specimens. Abundant treeferns gave evidence that rainfall in the area is distributed throughout the year. Although the plants were primarily green as described, the lower primary bracts and the upper leaves were suffused with bronze.
Tillandsia ponderosa is also epiphytic in pine and oak forests but in the highlands of Chiapas, Mexico's southern most state, and occurs southward into Central America as far as El Salvador. We have found this species at elevations between 6,000 and 7,500 feet in elevation. Here too the temperatures are low the year round and frequent rainfall and heavy fogs or clouds assure a constant supply of moisture. While T. laui, in spite of its large size, is not an especially ornamental plant due to the lack of coloration, T. ponderosa which has orange-red primary and floral bracts, is a highly ornamental species. It is collected by the local Indians at Christmas time for decoration.
Tillandsia laui Matuda by Renate Ehlers in Die Brom. 2: 42-43. 1995
Because T. laui in not one of the usual Tillandsias and nothing has been published in our Journal, I thought I should introduce a brief note about this plant:
T. laui was collected by Alfred Lau on 15. 7. 74 in Mexico, State of Oaxaca near Copala at 1800 m and described by Matuda in the Mexican Cactus and Succulent Journal. They assumed for a long time that this plant was only endemic to this area in Oaxaca.
In the meantime, we had found it established far wider in Mexico. We found it in Guerrero at Nuevo Delhi and near to Chilapa, in Oaxaca between Miahuatlan and San Gabriel and to our great surprise also in Chiapas. The finding in Chiapas was actually a mistake: for a long time we wanted to find a T. ponderosa growing there to flower in our own collection because one can observe a plant much better and can studyit better than at the location, where one never has enough time. We had had a small discussion with Paul Isley III as to whether the plants from Chiapas were really T. ponderosa, because the T. ponderosa from Guatemala are so different from those in his book. The plants from Chiapas are similar to T. imperialis, by having short, erect spikes covered by the primary bracts, whereas the plants from Guatemala usually have much longer spreading spikes. We now found between Comitan and St. Christobal a tall tree with several flowering T. ponderosa. The inflorescences were rather large for herbarium specimens and with much pushing and prodding with all our poles we were able to collect almost flowering size plants to take home. The following summer the plant developed an inflorescence. We were however very much surprised because the inflorescence remained completely green, whereas in the native location the magnificent pinecone shaped inflorescence shines intensively red through the green of the trees. We were still not cross because it sometimes happens that the UV-radiation is not sufficiently intensive with us and we don’t get the shining colour. Only when the first green flowers appeared did we realise: it was a Tillandsia laui. We had not known that this also occurred in Chiapas.
Our Bromeliad friend, Sue Gardner wrote about T. laui in the Journal of the Bromeliad Society, Vol. 31 p. 122, 1981. There she expressed the opinion that this was near to T. ponderosa by having more triangular, lepidote leaves and the larger size. Matuda, however was of the opinion that it was closer to T. imperialis.
However, T. ponderosa has primary bracts whose sheaths are clearly shorter than the spikes and spikes with to 8 sessile flowers and to 15 cm long, and I rather tend agree with the opinion of the author. Tillandsia laui flowers to 60 cm high and forms a large green funnel shaped rosette with many leaves. The scape is rather short, robust, with imbricate, green, foliate scape bracts with caudate, bent over blades. The inflorescence exceeds the rosette, is to 30 cm long, compound, dense cylindrical, the erect side spikes 4-5 cm long, to 4 cm wide, elliptic, complanate, short stemmed, with 4-5 flowers. The spikes are covered completely by the broad elliptical sheaths of the green primary bracts, exceeding the spikes, the narrow-triangular, strongly bent back blades of the lower spikes to 15 cm long, the upper ones gradually becoming shorter and rolled up. The floral bracts are dense imbricate, to 3 cm long, to 3,4 cm wide, acute, glabrous, leathery, green. The sepals are 2,7 cm long, 1,2 cm wide, leathery, glabrous, white-green, free. ( With all material examined by me, all 3 sepals were keeled and the posterior pair were connate 5 mm high). The petals form an erect tube with closed throat, is 6 cm long, white green. Style and stamens which exceed the flower, equally long.
Habitat Southern part of State of Oaxaca, Mex., and near Nuevo Delhi between Filhode Caballo and Paraiso, and near Chilapa, Guerrero. —SeeCact. Suc. Mex.
