Louisiana Society for Horticultural Research pp. 15-19 (1956)
Small-Flowering Chilean and Argentinian Amaryllids
Hamilton P. Traub

The narrow-leaved, small-flowering amaryllids from Chile and Argentina, commonly called Liliella by some, which are now grouped under the genus Rhodophiala Presl, present a neglected opportunity for gardeners over wide areas of the United States. In this paper the subject will be briefly reviewed.

Baker (1888) had reduced this genus of small-leaved, small-flowering plants to the synonymy of the broader-leaved, large-flowering group, Amaryllis L., on the basis of superficial external resemblances. These similarities are apparently due to parallel development from a very ancient common ancestral stock. A series of experiments has cleared up the confusion as to the relationship of these plants to other known genera.

The restored genus, Rhodophiala Presl

It was found that although the broader-leaved, large-flowering group, Amaryllis L., usually cross freely with one another, crosses of these with the narrow-leaved, small-flowering group could not be made. However, crosses between small-flowering species Rhodophiala bifida x R. chilensis have been made (Traub, 1952b). Then it was reported (Ficker, 1951) that the chromosome complement of the Rhodophiala species investigated was basic x=9 (2n=18) as contrasted with basic x=11 (2n=22, 44, 66) in Amaryllis L., which belongs in the Tribe Amarylleae. This suggested that Rhodophiala was not closely related to Amaryllis L., and that the former might belong in the Tribe Zephyrantheae, along with Habranthus and Zephyranthes.

To test this hypothesis, a series of breeding experiments was carried out (Traub, 1952b) . Rhodophiala bifida had been crossed with R. chilensis as already indicated. Now, R. bifida (from Argentina) was crossed with Habranthus juncifolius (from Argentina). Habranthus juncifolius was in turn crossed with Zephyranthes grandiflora (from Mexico) . Thus it was shown that Rhodophiala could be linked directly with Habranthus, and indirectly through the latter to Zephyranthes, both belonging in the Tribe Zephyrantheae. On the basis of these breeding experiments, it was necessary to restore Rhodophiala Presl as a valid biologic genus which is to be assigned to the Tribe Zephyrantheae (Traub, 1956) . This case shows the value of the experimental approach — through chromosome studies and breeding experiments in this instance — when such a complicated problem in taxonomy presents itself.

The restored genus Rhodophiala contains no less than 30 species (Traub, 1956) . These are native to Chile and Argentina. Unfortunately, only three or four of these are under cultivation in Europe and the United States. These are Rhodophiala bifida, R. chilensis, R. advena and R. pratensis. The writer has not been able to verify the last two as under cultivation in the United States, but they are reported in at least one collection in Europe.

Rhodophiala bifida, the Argentinian Liliella

There are three varieties of this species native to Argentina:

Rhodophiala var. bifida. Fall-blooming; flowers oxblood-red; spathe valves 2, free.

R. bifida var. spathacea. Fall-blooming; flowers lavender-pink; spathe usually single, split to the bae only on one side. Sold by van Tubergen under the name, "Habranthus roseus".

R. bifida var. pulchra. Flowers larger, white or light pink.

The first two varieties have been under cultivation in the United States for long over a half century, and they are fairly widely distributed. In some instances they have escaped from gardens and are growing wild. An experiment carried out by the writer (Traub, 1941) has shown that these two varieties are frost-hardy outdoors in Maryland. When planted in the open the leaves remained green and in good condition through the winter even after they had been subjected to snow and ice with a temperature drop to -4 F. (= -20 C.) Similar experiments should be carried out in other northern locations. In the South (including of course Louisiana), in Texas, southern Arizona, and California, these plants trive outdoors without any attention once they have been established. The very long, narrow leaves appear in the fall after the flowers have faded, and remain green over winter. They die down in early summer, and the bulbs remain dormant all summer. The bright flowers spring up like magic in the fall after a rain before the leaves appear. Rhodophiala bifida var. pulchra, which is reported as the most beautiful of the three, has never been introduced into the United States.

Rhodophiala chilensis, the Chilean Liliella

This is a most charming species, but is not widely grown in the United States at present.

Rhodophiala chilensis, native to Chile. Summer-blooming; flowers bright red or yellow. The pale yellow form is sold by van Tubergen as "Habranthus bagnoldii"

The pale yellow variety of this species has been introduced.

Rhodophiala pratensis (Poeppig)
Traub. Reproduced from plate 35, 1842
Botanical Register.

The pale yellow variety of this species has been introduced only recently into the United States. The writer obtained it from van Tubergen under the name, "Habranthus bagnoldii". When it flowered, it was identified as Amaryllis chilensis [=Rhodophiala chilensis} (Traub, 1952a). It is available from some plant dealers in the United States and it is gradually being distributed more widely. Fortunately, it is self-fertile so that propagation by seeds can speed up the distribution. The bright red form remains to be introduced from Chile.

The very long, narrow leaves of Rhodophiala chilensis are produced in summer with the flowers which appear in succession until fall. The foliage dies down in winter and emerges again in summer.

Other Introduced Species (?)

Rhodophiala advena, native to Chile. Fall-blooming; flowers yellow or red.

Rhodophiala pratensis, native to Chile. Spring-blooming; flowers bright red or violet-purple.

The writer had had reports (see Traub & Moldenke, 1949, p. 91, 100) that these species were extensively cultivated in the United States, but he has found later on checking these reports that authentic plants could not be obtained. In all cases, they turned out to be Rhodophiala bifida varieties bifida and spathacea to which the names advena or pratensis had been erroneously applied.

In 1955, Miss Josephine Henry, of Gladyne, Pennsylvania, brought back several Rhodophiala species from Chile, but these have not as yet been identified. A report on these will appear later.

Hybrid Rhodophiala

The writer has crossed Rhodophiala bifida and R. chilensis (Traub, 1952b). In the first generation progeny, the summer-growing habit of R. chilensis, and the flower-color of R. bifida, either oxblood-red or lavender-pink as the case may be, are dominant. A second generation has been raised by selfing the first generations hybrids in 1956, but it will be a year or two before these seedlings flower. A report on the segregation of characters in the second generation will be made when flowers are obtained. With the introduction of other species, the production of various other hybrids will present a fertile field for the amaryllid hybridizer. This is surely a neglected opportunity.

Work for the Future

More than twenty species of Rhodophiala remain to be introduced into the United States from Chile and Argentina. Since these plants would be a valuable addition to our garden flora, it is urgent that more of them be made available to gardeners.

These plants are of easy culture and will take care of themselves once they become established. The bulbs are deeply seated in the ground, and seedlings will pull themselves down to the natural level. Thus the bulb dealer will have a problem in digging the bulbs. The color range of the flowers is impressive, including bicolors and polychromes — white, yellow-green, lemon-yellow, yellow & red, rose, rose-red, lavender-pink, light pink, red, oxblood-red, scarlet, scarlet-orange-yellow, scarlet & yellow, purple, and violet-purple.

It should be noted that there are spring-, summer- and fall-blooming species so that they could brighten the garden for a long time during the growing period. They can be naturalized like Narcissus in public parks where they would make grand displays if grown by the thousands.

The best method of propagation is by seeds, although offsets are produced liberally in Rhodophiala bifida and possibly also in other species. By means of seeds thousands can be raised in a relatively short time.

Literature cited