THE JOURNAL OF THE BROMELIAD SOCIETY|
Editorial Office—647 South Saltair Avenue
Los Angeles, Calif. 90049
The Journal is the official publication of the Bromeliad Society, a non-profit corporation organized in 1950. Subscription is included in the membership dues. There are six classes of membership: Annual, $7.50; Sustaining, $12.50; Fellowship, $20.00; Commercial, $25.00 and Life, $150.00. For membership information, write to Mrs. Jeanne Woodbury, 1811 Edgecliffe Drive, Los Angeles, California 90026.
President—William R. Paylen, 1008 Gretna Green Way, Los Angeles, Calif. 90049|
First Vice-President—Elmer J. Lorenz, 5110 Monte Bonito Dr., Los Angeles, Calif. 90049
Second Vice-President—Eric Knobloch, Box 121 Braithwaite, La. 70040
Secretary—Lottie Cave, 7453 Denny Ave., Sun Valley, Calif. 91352
Membership Secretary—Jeanne Woodbury, 1811 Edgecliffe Dr., Los Angeles, Calif. 90026
Treasurer—Laurel Woodley, 1250 N. Bundy Ave., Los Angeles, Calif. 90049
|David Barry, Jr. 11977 San Vicente Blvd., Los Angeles, Calif. 90049||Awards|
|David H. Benzing, Oberlin College, Oberlin, Ohio 44074||Research|
|Edward McWilliams, University of Michigan, Ann Arbor, Mich. 48105||Research|
|Eric R. Knoblock, Box 121, Braithwaite, La. 70040||Program Aids|
|John Riley, 3370 Princeton Court, Santa Clara, Calif. 95051||Education|
|George Kalmbacher, Brooklyn Botanic Garden, Brooklyn, N. Y. 11225||Study Course|
|Ervin Wurthmann, 5602 Theresa Rd., Tampa, Florida 33615||Cultural Aids|
|Patrick Mitchell, 8211 Helmers St., Houston, Texas 77022||Affiliated Societies|
|Ralph Spencer, 2620 Via Rivera, Palos Verdes Estates, Calif. 90274||Slide Library|
|Wilbur Wood, 1621 Irving Ave., Glendale, Calif. 91201||Hybrid Registration|
|Kelsey Williams, 7430 Crescent Ave., Buena Park, Calif. 90620||Promotion|
|Elmer Lorenz, 5110 Monte Bonito Dr., Los Angeles, Calif. 90041||Display Notes|
|William Paylen, 1008 Gretna Green Way, Los Angeles, Calif. 90049||Advertising|
|George Milstein, 33-55 14th St., Long Island City, N. Y. 11106||Programing|
|William Dunbar, 11444 Ayrshire Rd., Los Angeles, Calif. 90049||Legal Adviser|
Adda Abendroth, Brazil
Luis Ariza-Julia, Dominican Republic
Olwen Ferris, Australia
Mulford B. Foster, U.S.A.
Marcel Lecoufle, France
Harold Martin, New Zealand
Richard Oeser, Germany
Prof. D. W. Rauh, Germany
Raulino Reitz, Brasil
Walter Richter, Germany
Dr. L. B. Smith, U.S.A.
Robert G. Wilson, Costa Rica
Julian Marnier-Lapostolle, France
This Nidularium hybrid is known in Europe as N. × 'Mignon' (Gulz), in the United States as N. × 'Memoria' (Hummel). It is a cross of N. lingulata var. lingulata × N. lingulata var. minor. Photo by Jeanne Woodbury.
|Tillandsia recurvata growing on telephone wires.|
Before leaving on December 11, 1970, for Rio de Janeiro by plane I had sent out air mail letters to a few English-speaking persons who I felt might help me on my botanical venture. I suggested that they write me at the Gloria Hotel in Rio where I had reservations. However, due to the Christmas mail rush, Padre Raulino Reitz and Guido Pabst, Director of Varig Airlines, received my letters about three weeks late and, therefore, could not reach me in time. Fortunately, my letter to Adda Abendroth, Honorary Trustee of the Society, was delivered in time, and so there was a very friendly letter from her awaiting me on my arrival.
Going from the freezing north to extreme tropical heat, getting little sleep on the plane, waiting in a long line at customs, then fighting miserable traffic to the hotel—all this meant resting up nearly all the day of arrival until I could get physically organized.
But on the next day (Sunday) I went to the Rio Botanical Garden—and it was a day of joy. The first big shrub I looked at had Tillandsias growing on it—a number of small ones, and as I looked around I saw these and other epiphytes all over the place. The Garden is an old one, dating back to 1808, and there were many large and old trees containing a world of epiphytes. Rhipsalis (epiphytic cacti) displayed curtains of long slender streamers.
|Vriesea regina at the Botanic Gardens in Rio de Janeiro.|
The Botanic Garden is so situated that it has high hills behind it. These were usually covered with clouds on those days I was there and rain developed in the evening. There is no rain forest around Rio, but there is plenty of rainfall so that the woody vegetation is lush, and plenty of moisture encourages epiphytic growth.
There are five species of Tillandsia that may be found in the Botanic Garden: stricta, tricholepis, geminiflora, recurvata, and gardneri. It was exciting to note that evidently seed lodged and germinated on the underside of branchlets, and that short and long roots could be seen growing ahead of the plants on top of the branches as well as into the atmosphere. The plants worked upwards, so that in time a bushy little Tillandsia looked as if it were growing on top of the branch all the time.
Since there is so much organic debris in trees of tropical woods with heavy rains, organic juices on horizontal or nearly horizontal limbs are constantly being washed down the sides, and much of this liquid matter will find its way to the lower side of twigs to cling to tiny fissures. Probably this broth stimulates the seeds of Tillandsias which also wash down the sides of the limbs to sprout.
The first day of "exploration" presented me in the botanic garden the finest bromeliad sight I was to see in my stay in Brazil. It was a magnificent flowering specimen of Vriesea regina leaning toward a little pond next to which it was growing. The flowering stalk which was about seven feet high, the outstanding red of the stout axis with the obvious large lower bracts, and the outstretching branches with large flowers made a glorious picture a triumph of creation. The flowers were long and narrow, and the stamens were far exserted above the petals, a character that added to their beauty.
On another day in the garden I was shown a collection of bromeliads hung in baskets in a large pergola. These had been accumulated by a former staff member no longer with the garden. There were no identifying names. This big collection was of doubtful value because no one had been assigned to continue its educational usefulness. This lack of interest in bromeliads on the part of the management of the Garden shows itself in the fact that one does not find any of the bromeliads named. What a pity that in this land of great bromeliad wealth there is no large identifiable collection of these plants growing under conditions that are natural to them to offer knowledge to a ready, eager world of amateurs and scientists.
Roaming around the grounds on other occasions I found the ferociously spined Pseudananas sagenarius with its large cone-like red-bracted inflorescence. In another spot I found growing on the ground in flower Billbergia pyramidalis. Whether this was an especially fine form or whether this was the natural condition for this plant here, I do not know, but I was highly impressed with its stout large inflorescence and the rich colors of the flowers. It is native to the Rio area.
|Tillandsia gardneri growing on Gardenia thunbergia in Botanic Garden at Rio de Janeiro. Fruit is that of G. thunbergia.|
On Monday morning I went to the Administration Building at the Botanic Garden and to my distress could find no one who could speak English. Things looked "sort of blue" for a while, but I was given an escort to take me to the other end of this large garden to the new headquarters of the Systematic Botany Section, and there I found Dimitri Sucre who speaks English. He is a Panamanian who came to Brazil to take up a career as botanist on the staff of the Garden. He was friendly, helpful, enthusiastic, and made me happy with discussions and information. I suggested that his name Dimitri did not sound Latin American to me, and he said that his mother was fond of Tolstoy and had named all her children after characters in Tolstoy's novels.
An interesting bromeliad from the state of Bahia growing in the collection at the Systematic Section was Orthophytum maracasense. Its long narrow leaves each arch outwards and downwards in strong graceful curves. These are a cheerful light green-grey and about a foot long. The edges are closely spined.
I paid visits to Adda Abendroth on two different days. To get to the mountain city of Teresopolis which was her home at that time, I took a bus ride of two hours and forty minutes, the last part a steep scenic climb into the mountains. The yard around her home was small, but in the tropics where epiphytes can be grown outdoors, the vertical possibilities of establishing orchids, cacti, and bromeliads, especially small ones like Tillandsias, make up for lack of space. Her ground was crowded with, among other things, many bromeliads such as Vriesea bituminosa, Neoregelias of several kinds, Aechmea fasciata, and A. nudicaulis of which she had collected three different forms.
|Vriesea bituminosa growing on tree in the Organo Mts. Reserve.|
Hers was not the common garden of temperature climates. There are very narrow irregular paths, and one must now and then bend down not to disturb some perching plant and also be careful not to walk hastily and brush against attached plants. She had some Spanish moss, and though it was out of season for flowering, we found two tiny blossoms. (When I visited the Bragas in their mountain home, I inspected the Spanish moss there and, sure enough, there were two flowers also in blossom close to each other.) Well, to sum up Adda's garden: it was a green heaven with color, of choice collected things, pretty much from her own area, and had been for her a constant source of study and enjoyment.
Adda, gifted amateur naturalist, was making observations on a certain kind of small frogs that were spending their time in her bromeliad "vases," sometimes in one species of bromeliads, sometimes in another. She scouted around so that she could find them and point them out to me. They sit in the tube with their heads looking outward, on the watch; she gave them food, and they were, in part, her free pets.
Concerning bromeliads, I asked her various questions, and here are some of her observations. Aechmea fasciata is a night bloomer. The flowers stay open until about 10 A.M. on bright days, but on cloudy damp days they do not close until about noon. On dry days, even if there is no sun, they close at about 10 A.M. Neoregelia flowers are open from about 8 or 9 in the morning until about 2 in the afternoon.
On one of my trips to Adda, her friend, Beatrice Orrsich, drove Adda and me to the National Forest Reserve in the Organ Mountains. A little inside the entrance, as part of an attractively laid out park, there was a big collection of large bromeliads on a rocky, steep slope. They had been acquired several years ago by a person interested in the pineapple family and have flourished, expanding where they can. There were large clumps of several different Neoregelias, and Vriesea bituminosa was growing on rocks as well as on trees a little higher up the hillside. Nothing was named. We three walked about a mile up the mountain. Several kinds of bamboos had been planted years ago on each side of the road. These were spreading so much that it will be a monstrous problem to keep them in control.
Beatrice Orrsich took us to her home, a happy little place—cozy home and small garden. There she had some few Tillandsias, but her plants indicate a general taste with some emphasis on cacti. One plant that she has is of special interest—the rare Blue Amaryllis of Brazil. By some authorities it is called Worsleya rayneri, The estimable Royal Horticultural Society's Dictionary of Gardening (England) calls it Hippeastrum procerum. It was not flowering, so that I did not see the flowers which are six or more inches long and 4 to 5 inches wide. The color is light lavender, with or without a white median stripe. The leaves spread upward and outward like a fan, and Beatrice told me it is popularly called "Tail of the Rooster" in Brazil. It grows on rocks, and she stated that it is difficult to maintain in cultivation, that it lasts a maximum of only three or four years.
(to be continued)
Water containing appreciable amounts of certain salts, primarily those of calcium, forms an insoluble curd with soap and thus presents difficulties in washing. These difficulties are overcome by removing the calcium; the natural or synthetic zeolites, and ion-exchange resins having the same function, accomplish the removal by substituting sodium for the calcium. Water softened in this fashion, however, is not suited for use on bromeliads, as it contains sodium salts in about the same quantity as the original content of calcium salts, and in the leaf cups of the plants these in time become concentrated enough to injure the plant tissues.
However, by use of two types of ion-exchange materials in combination it is possible to remove salts completely as both positive and negative ions are stripped out. Water so treated, "de-ionized water," is equivalent to distilled water and contains nothing injurious to plants. Laboratory-supply houses can furnish packed columns for purifying water in this way. Cost may be a deterrent; the cost per gallon of purified water will depend on the mineral load in the water treated.
Rain water is of course the most abundant "soft" water. Other sources are the condensates from air-conditioning and dehumidifying units, and the water from defrosting electric refrigerators.
—Roger K. Taylor, Winter Garden Florida.
GEORGE MILSTEINThe first thing that has puzzled me regarding variegated bromeliads is what I consider their most beautiful aspect. What I am referring to, of course, is the reddening of the white areas, causing in many varieties a "tricolor" effect. However, in many of the variegated types, the white areas remain white, regardless of the amount of light the leaf surfaces receive. What causes the type of variegation we have in the Bromeliaceae, rather than the random leaf mottling found in other plant families, is the fact that bromeliad leaves, like blades of grass, are composed of parallel fibers and variegated stripes naturally follow along these longitudinally situated fibers.
What causes the variegation is the loss of the chlorophyll-producing ability of the cells that initiate these stripes, but another important occurrence must take place in these fibers, and that is another phenomenon that bromeliads are noted for. David Benzing of Oberlin College, Ohio, is doing definitive research in this area, and hopefully we will all soon benefit from the published results of his experiments. I am talking about the hormonal or chemical changes that appear in bromeliad leaves when they are initiating blooming or when they are being grown in intense light. Of course, the reason for the first-named phenomenon is nature's way of attracting some form of animal life to aid in either pollination or seed scattering. In the latter case, the reddening of the foliage is a protective measure to help screen out the harmful effects of the sun's rays just as does the tanning of human skin.
When bromeliads variegate, there are many forms that this variegation can take. In many varieties, the variegation destruction of chlorophyll production is either incomplete or it regenerates either naturally or because of the effect of growing conditions. Probably the commonest example of this is Billbergia pyramidalis var. striata. Here the variegated striping occurs only as a paler green as against the darker natural coloring of the original. Even under the best of growing conditions, the stripes never lose their green coloring completely. This has been noticed in many of the Billbergia variegations, Billbergia × 'Santa Barbara,' for instance. What is more remarkable is that this type of variegation is completely dependent on good light conditions. When grown under inadequate lighting, these plants appear to be an unvariegated green. In B. pyramidalis var. striata the variegation never takes on even a slight reddish color, even though the original B. pyramidalis frequently colors up pinkish under strong light, while B. × 'Santa Barbara' will turn its light colored stripes a bright red.
Another type of variegation is the one where there is apparently a regeneration of the chlorophyll production as the leaves mature. A prime example is Canistrum lindenii var. exiguum. In this species the newly developed leaves exhibit a very clearly defined variegation which gradually disappears as the leaves get older.
The third variety of variegation is the type of red striping that occurs in a sport of Aechmea × 'Foster's Favorite' called A. × 'Red Ribbon.' Here the variegation seems to be initiated in the cells that control the red coloring in the leaves. Almost every bromeliad enthusiast knows that A. × 'Foster's Favorite' is best grown in a medium or subdued light condition. My plant was grown directly under "Vitalite" florescent tubes, and here the effect has been the same as direct sunlight. The upper portion of each leaf which was closer to the light source has completely lost the red striping, whereas the lower part of the leaf which received less light demonstrated the red striping rather forcefully. This same red striping occurred in a variegated form of Guzmania musaica.
Number four on my list includes the pure white or ivory-colored striations. These take two forms: some become strong bright red or pink and others remain pure white regardless of the amount of light received by the leaf surface. It should be noted that in line with what was said earlier about the red coloring acting as a protection against strong actinic rays, the varieties that do not develop the red but remain white or cream colored do best if grown under subdued light conditions. Prime examples of this behavior are best illustrated by two varieties found in practically every bromeliad collection. These are Neoregelia carolinae var. tricolor and Nidularium innocentii var. lineatum. The first colors beautifully in all the light colored areas with the characteristic solid red center so characteristic of N. carolinae. This plant can take a lot of light, in fact, must have it to develop the brilliant color. The second plant develops central visible bracts which are also striated. Though the bracts color up as would the bracts of any inflorescencing Nid. innocentii, in this case, it is only the green portions of the bracts which color red; the white striations remain white, giving the inflorescence a much paler appearance. Another point is that A. × 'Foster's Favorite Favorite,' which can take bright light and does turn a bright red all over, though the original A. × 'Foster's Favorite' will develop a washed-out appearance when grown in strong light. Another popular species which develops two popular variegations, A. fasciata var. variegata and A. fasciata var. albomarginata, rarely develops any red coloring in the striations. The same can be said for, among others, Tillandsia viridifolia var. variegata, A. nudicaulis var. variegata, A. caudata var. variegata, and A. coelestis var. albomarginata.
Last is the tendency of many of the albomarginata varieties to produce albino or rather pseudo-albino offsets. I call them pseudo albinos because if they were true albinos, they would completely lose their ability to produce the green coloring of chlorophyll. However, almost every all-white plant, such as in the offsets of Ae. fasciata var. albomarginata, C. bromelioides var. tricolor, and C. × 'It,' lose their albinism when mature, proving that at least a small percentage of the chloroplasts began to recover from their dormant stage.
Almost every bromeliad grower has noted the phenomenon of the pink or red coloration of newly emerging offsets of many species and varieties. In many cases, this color may remain as the offset matures. In almost every case, this coloring, which I presume is again a natural protective measure against strong light damage, disappears completely as the plant reaches full size.
As the title of this little article suggests, what I have written are only random thoughts. I do not presume to have mentioned everything to be said on the subject. Since most of my thoughts have been stimulated by the plants I grow in my apartment, I hope others who grow their plants outdoors and can observe many more plants that I possibly could can add to this knowledge.
ADDA ABENDROTHFritziana goeldii seems to be the most common of the Organ Mountain frogs that spend much or all of their lives in close connection with bromeliads. The little hopper is classed among the tree-frogs, but it needs bromels much more than trees because it takes refuge between the leaf sheaths and uses the pond as a nursery for its babies. Bromeliads live up on the trees as much as on the ground and on rock.
My first Fritzianas came into our garden without my knowing; they were hidden in the bromels I had collected in the forest. I learned more about them from a zoologist friend. One day when he came to see us I had a Billbergia pyramidalis flowering in the sitting room, and when night fell a cricket-like sound issued from the bromel tube. The scientist explained that it came from a frog hidden in the bromel heart and that I must be sure and put the plant outdoors at night to give the animal a chance to forage and then it would return to the tube next morning. I was much interested and from then on gave the free lodgers closer observation.
It was a disappointing engagement. The frogs have a fabulous capacity to change their looks and manners, their color and size, their habits and whereabouts. But as the years passed I did learn a little from watching the animals and their activities. The following is an account of what I saw, focusing especially on the frogs' ties with bromeliads.
On the whole I get the impression Fritzianas lead a gregarious life. They know their kin and know bromels and do not venture far away from them. Always a number of them inhabit the same area. Each seems to know which way to turn to find its brother and how to locate a convenient bromeliad. They are a peaceful little people.
Fritziana goeldii is a nondescript little frog rarely more than a few cm long. Variously patterned it looks darkish in the daytime and fades to grayish at night. It has no conspicuous markings except in the case of females in egg-time. Ten to sixteen eggs lined up neatly on a small frog's back is a sure identification mark of the species. Another sure sign is the voice.
The voice, however, is seldom heard in the daytime, not at all on dry, sunny days. An overcast sky and forebodings of rain call forth the frogs' happy comment. So does the spray of a garden hose. In the evening about half an hour after sunset, except in very dry weather, one little frog starts calling with a series of soft short notes. Soon other males in the neighborhood respond, and a chorus gets going. A tune lasts from 40 to 50 seconds, then dies, to be repeated about ten minutes later. This musicale goes on for an hour or so. In our southern spring beginning in October, the voices are louder, and the performance may last until midnight.
The Goeldiis of the Organ Mountains prefer tubular bromels in which to live. I found them sleeping for hours on end in the narrow tube of a Billbergia vittata, B. amoena, B. horrida; Aechmea pineliana varieties, Ae. nudicaulis var. aureo-rosea, cuspidata, and former var. cornuii; Quesnelia marmorata and liboniana; and tubular Neoregelias. The frogs sleep nose-up. Inside the tube they always take that position. Backwards they run from the tip of the leaf to its base. Ordinarily only one animal lives in a tube. In times of drought several may take refuge in the large Vrieseas.
Towards nightfall the frogs wake up. Step by step they come out of hiding, skip to a nearby branch, then to other branches, onto shrubs, and up into trees. Soon the chorus is in full swing. The frogs may stay for hours in a spot they select. Next morning they are back in their tubes. Occasionally they move to a new tube when the old one dries or if it develops a flower spike.
Inside the tube the frog clings to the outer wall, motionless, eyes half closed. Any disturbance in the neighborhood makes him withdraw to the bottom, out of sight. Some of mine disappear as soon as they "feel" me approaching on my morning round. Half an hour later they are back a little above water level. Sometimes one takes a sun bath a little further up.
At night I see the males slowly jumping on the leaves of large Vrieseas, pausing for a rest between advances. Large Vrieseas serve as day shelters on very dry days. In spiny bromels frogs change to the underside of a leaf sideways or head-on and do not seem in the least embarrassed when a long sharp spine pokes into their belly.
Mating is thought to occur inside a tube. In spring I have seen couples there maintaining an unchanged position for 40 hours in succession. A few days later a female with eggs on her back emerged. She stayed in that tube for over a month until it was time to drop the eggs. Meanwhile a male or two hang around as if to keep watch over her. Now mother wants to move to a larger bromel with plenty of water for the children to play in, something with a spreading open rosette of an Aechmea. Do the males find her a suitable place and guide her to it?
When the female has left her brooding tube, I examine suitable broms around in search of the nursery. Where I see the water slightly turbid I stop and stare at the water level while I count to sixty. If my guess is correct I see a little gray ball rise from the depths and vanish again in a jiffy before a minute is over. The hall holds a tadpole struggling out of its egg-skin. In a day or two it will succeed. Then gradually the limbs develop, hindlegs, forearms clasping the yolk to the chest, eyes and nose can be seen with a lens, the tail shrivels. The new little beast looks somewhat like a housefly. One morning I find it and brothers and sisters of the same clutch, plus perhaps a few from another female's clutch, all lined up side by side in the pond just above the water. In one nursery I counted 20. They are finally developed, ready to take off. A few moments later they shoot up into the air nearly 2 m high, as if driven by a secret force suggesting forerunners of the modern missile. From then on each is on his own. They grow fast, spending their days sleeping in bromel tubes.
It was with a feeling of much relief that we learned that the Bromeliad Society of Broward County, Fort Lauderdale, Florida is taking on the task of registering the hybrids of the late Ralph W. Davis of Miami. Mr. Davis had made many exceptionally fine crosses, and it was feared that these would be lost. Now under the chairmanship of Irma Gall, these many beautiful bromeliads will be officially registered and in time propagated so that they may be procured by interested growers.
The first registration received is that of a bigeneric hybrid, Neomea × Mem. Ralph Davis. It is a cross between Neoregelia Johannis rubra and Aechmea chantinii. The cross was made in 1965 and flowered for the first time in March, 1971. The foliage is pale green with darker crossbands. The bracts are rose; the petals are white.
WERNER RAUH, NESTA EHLER, AND RAINER SCHILLIn our studies on the morphology and taxonomy of the bromeliads, we have now started on the investigation of their pollen-morphology. The aim of these inquiries is to find out how far the shape and size of the pollengrains and the structure of their membrane (sexine) might be helpful in underlying a more natural classification of the different genera than morphological characteristics alone can do.
Every bromeliad collector and amateur knows the difficulties to distinguish, for example, a Tillandsia from a Vriesea. We know that gray, atmospheric, very lepidote Vrieseas greatly resemble Tillandsias, and on the other hand we know green Tillandsias bearing a great resemblance to Vrieseas. The only difference between the two genera exists in the flower structure: the petals of Vrieseas bear on the upper side, near their base, two small, deciduous scales, lacking to the flowers of all Tillandsias. As these scales are often difficult to detect even in living material and will generally be overlooked in dried specimens, it is no wonder that many Vrieseas have been described as Tillandsias. Having made a revision of the genus Vriesea is the great achievement of the bromeliad-expert, Lyman B. Smith from the Smithsonian Institution, Washington.
Now the possibility has come to recognize further characteristic structures which will help discern the different genera more easily. For some years past Palynology (pollen morphology) has evolved into an auxiliary science of great importance for the elucidation of taxonomic problems. In fact, pollen-morphology of bromeliads has already been studied to a certain extent just with the assistance of normal light-microscopes. Decades ago Harms (in Naturliche Pflanzenfamilien, Vol. XV a, p. 100, 1930) proposed, for example, the following subdivision of the subfamily Bromelioideae according to the shape of the pollengrains:
a. Archaeobromeliae: pollengrains without a porus or sulcus.
b. Poratae: pollengrains with pori.
c. Sulcatae: pollengrains with a longitudinal sulcus (fig. 1-4, fig. 9). But, this is just a superficial classification. With the help of a normal light microscope we can see these differences, but nothing else.
Today, by means of better instruments, as electronic microscopes, we are in a position to investigate even submicroscopic structures. For palynological research the scanning electronic microscope "Stereoscan" has proved to be the best instrument, and it has opened a promising field of investigation. The great advantage of this microscope is quite obvious: The pollengrains are portrayed in a stereoscopic photograph, and by the powerful enlargement all those submicroscopic structures of their surface can be detected which can be used as criteria for a more detailed classification of different genera, perhaps even of different, but closely related species.
|Fig. 1 — Tillandsia grandis Schlecht. Ca 1500 ×|
In the following pages we present some photographs of our recent investigations. First, some words as to the method of preparation. The pollengrains were mostly taken from imported plants, which were collected by W. Rauh during his expeditions to South and Central America, and which are cultivated now in the Botanical Garden of the Heidelberg University. For the electronic-microscopic examination, the pollengrains were dried under vacuum and shadowcast with carbon-gold. The photographs were taken in a magnification of 1000 × to 10,000 ×.
We begin with several representatives of the subfamily Tillandsioideae, as Tillandsia, Vriesea, and Guzmania (fig. 1-3). Their pollengrains are longish and sulcate, differing just by their size (30 um - 90 um). In other respects we cannot find out remarkable structural differences except by means of the Stereoscanning electronic microscope.
In Tillandsia the surface of the sexine is covered with fossettes of various extension and the two terminal poles are more or less smooth. (Fig. 1) In Vriesea and Guzmania the sexine shows a reticulate structure. Whereas in Vriesea the muri (i.e. the walls of the fosettes) are comparatively thin (Fig. 2, 2a), they are thick in Guzmania, and from the bottom of the brochi (i.e. the fossettes) small papillas stand out (fig. 3, 3a) lacking the pollengrains of Vriesea.
The Stereoscan-pictures prove the possibility of discerning easily the three genera just according to the structure of the pollengrain membrane.
|Fig. 2 — Vriesea saundersii (Koch) Morren Ca 200 ×|
|Fig. 2a — Vriesea saundersii (Koch) Morren Ca 5000 ×|
|Fig. 3 — Guzmania Mucronata (Griseb.) Mez. Ca 2000 ×|
|Fig. 3a 10,000 ×|
We can show the same in several representatives of the subfamily Bromelioideae by pictures of pollengrains from Aechmea, Billbergia, and Neoregelia.
Within the Bromelioideae we find two different types of pollengrains:
- sulcate pollengrains, resembling those of the Tillandsioideae.
To this type belong, according to our research, Billbergia (Fig. 4, 4a) and Orthophytum for example. The structure of the sexine in Billbergia is reticulate, in detail hetero-reticulate. The muri are thin and from the bottom of the brochi arise micropapillas as in Guzmania. (Fig. 4a)
- The other type of pollengrains is represented in Aechmea,
Neoregelia, Nidularium, and Wittrockia.
These pollengrains are cylindrical, diaperturate (not sulcate) and characterized by the two smooth hemispheric polar ends (Fig. 5-7). In all these species the structure of the sexine is reticulate, but different in the single genera. Whereas the reticulum in Aechmea is very regular (Fig. 8a) and the brochi have no papillas, in Neoregelia many muri are unconnected and ending blind (Fig. 8b) and from the bottom of the brochi arise micropapillas (Fig. 8b).
The few examples demonstrated here prove the utility of pollenmorphology for the elucidation of taxonomic problems, but we cannot renounce the morphology of the plant and of the flower structure in our effort to erect a natural system of the bromeliads.
Our preliminary research will be continued on a broad basis and published later. Acknowledgments: We are greatly indebted to Dr. Ing. H. Klingele, 8 Munchen 22, Adelgundenstr. 8, for the photographs and Dr. H. Uhlarz, Heidelberg, for the translation of our article.
—Institute of Systematic Botany, University of Heidelberg, W. Germany.
|Fig. 4 Billbergia morelii Brogn. Ca 1000 x|
|Fig. 4a Ca 5000 x|
|Fig. 5 Aechmea Kerteziae Reitz Ca 2000 x|
|Fig. 6 Neoregelia farinosa (Ule) L. B. Smith Ca 1000 x|
|Fig. 7 Wittrockia amazonica (Baker) L. B. Smith Ca 2500 x|
|Fig. 8a Neoregelia farinosa (Ule) L. B. Smith Ca 5000 x|
|Fig. 8b Aechmea kerteziae Reitz Ca 5000 x|
|Fig. 9a Hechtia spec. Ca 2000 x|
|Fig. 9b Puya species Ca 2000 ×|
Several other changes in nomenclature are noted: Vriesea splendens var. longibracteata is now officially V. splendens var. formosa, this name dating back to 1889. Tillandsia atroviridipetala is now officially T. plumosa.
|AECHMEA × RAKETE|
The handsome Aechmea is one of Walter Richter's fine hybrids. The cross A. nudicaulis by A. fulgens var. discolor was made in 1947 and flowered in 1950. It is a medium-large to large plant with foliage like that of the seed parent, being green above and maroon beneath. The inflorescence shows the influence of A. nudicaulis.