Tillandsia xiphioides was described in 1816 by Ker Gawler in Botanical Register 2: t. 105 (and accompanying text) from Buenos Aires, Argentina (the species is not currently known from this area). It is doubtful if a specimen has been preserved as the type (Smith & Downs 1977), but the species is well typified by the plate (Fig. 1). It seems to me that the typical specimen is a relatively large one, with spreading leaves, that can be compared in size with the clone in Fig 2. That plant is also visible in Figure 4b.

Tillandsia xiphioides also grows in Bolivia and one doubtful record is known from Rio Grande do Sul, Brazil (specimen not seen). It belongs to the subgenus Anoplophytum, having flowers with spreading petal blades and the narrow petal claws forming a tube, included stamens (often with plicate filaments) and the slender style with the stigma often emerging from the throat of the corolla.

The species has a large distribution over Argentina and Bolivia and is highly variable and although 3 varieties and 1 subspecies have already been described (for a distribution map see Hromadnik, 1989), this does not cover the whole range of variation. It seems that there are many distinct ecotypes and plants from numerous local populations look different. Differences are found in plant size, succulence, leaf arrangement (more-or-less secund or spreading), leaf pubescence (densely lepidote to tomentose, and cinereous-green to silvery white), and the size and number of flowers in the spikes (many forms are typically 2- or 3-flowered, but some are up to 7-(10-)flowered).

The smallest form known to me (Fig.3) is from South Bolivia, Tarija --near Entre Rios, 2800 m elevation. The same small, very succulent form has been collected in the same province by Renate Ehlers (see Fig. 10). This is a very delicate and compact form that changes habit in cultivation depending on growing conditions. In my private collection it seems to grow smaller each year and did not flower up till now (Fig. 3). At the Utrecht Botanical Garden, where it gets fertilization on a regular schedule along with more space and light during the winter, it grows much faster and flowers regularly. At the moment I'm growing also a piece from the plant collected by Renate Ehlers (Fig. 4d) and it has just started producing an inflorescence. I am hoping some flowers will develop later this year.

Often Tillandsia xiphioides starts to make a spike in autumn, but then develops very slowly or stops before producing any flower in winter. My small greenhouse is situated WNW at the back of my house, which is bad for light conditions during winter. This...