Tillandsia ilseana W.Till, Halbritter & Zecher
Literature references:
Comments:
- According to Gardner (1986), the new species belongs to group I, subgroup III. Using the Smith & Downs monograph (1977), the plant keys out to Tillandsia bourgaei Baker, the nearest related species, but T. ilseana differs from
T. bourgaei in the following characters: broader rosettes, shorter leaves, scape bracts often surpassing the lower inflorescence which is rather dense, broader primary bracts, elliptical and more flowered spikes, shorter and broader floral bracts which are nearly equal to the sepals, lepidote and posteriorly short connate sepals, and shorter yellow-green petals.
Tillandsia ilseana differs from T. roseospicata Matuda state of Mexico, in larger habit, smaller leaf sheaths and narrower blades, an inflorescence with fewer spikes, much shorter primary bracts, in spreading and narrower spikes, narrower floral bracts, posteriorly 8-9 mm high connate sepals, the longer, white petals and stamens and style which arc distinctly longer than the corolla
No congruence has been found with other recently described species from this subgenus.
The pollen grains of Tillandsia ilseana (fig. 6) were elongated, heteropolar, monosulcate, and about 60 micrometers in diameter (longest axis). The exine is rather thin and reticulate with meshes of various sizes. Pollen surface, pollen size and the shape of the slender furrow are characters of subgenus Tillandsia. It is of special interest that the pollen grains of subgen. Tillandsia are very similar to or nearly identical with those of many Vriesea species. This observation supports the idea that Tillandsia subgen. Tillandsia (and most probably subgen. Allardtia, too) is more closely related to most Vriesea species than to other subgenera of Tillandsia, judging from pollen characters. We are aware that this opinion is contrary to that of Schill & al. (1988).
A short comment should be made about the phenology of the new species. In culture, flowering began in the first days of April and ended one month later. In the lowermost two spikes of a 15-spiked inflorescence the first flower appeared in the axil of the eighth bract, in spikes 3-10 in the seventh bract, and in spikes 11-15 in the sixth bract. The first 5-7 bracts of each spike are sterile, the spikes are 8-10 bracteate but 3-5 flowered. The very first flower appeared in the terminal spike, then flowers followed in the two lowest spikes, and finally in the middle spikes. This pattern is more or less repeated by the subsequent flowers. Each flower opened in the early evening and began to fade in the late morning of the next day. In late flowering stages a conspicuous drop of tasteless, colourless liquor appeared at the top of the stigma, obviously to prevent a second pollination.
We thank Dr. E. Vitek and Dr. M. Kiehn, both of the University of Vienna, for providing the colour slides for figures 3 and 4 respectively.
NOTE
Ehlers has explored the Type locality on 2 separate occasions and not found this plant. Is it a natural hybrid? The odd colour of the petal suggests it might be. Other species from Type locality are T. chalmaensis, T. pentasticha, T. prodigiosa, T. bourgaei. A favoured contender for one parent would be T. pentasticha.
Lieselotte Hromadnik found a lot of plants near Yextla, between Corral de Bravo and Ventos Frios. - Email 4 Oct 2005 —See Till et al. 1989b p. 39(4):152-156
