For many years past some few species of pandanus have occupied quite a prominent place among decorative plants, and this is deservedly so, from the fact that the members of this genus in general are not difficult to manage, and are also quite rapid growers under favorable conditions.
The well-known P. Veitchii and P. utitis are two of our very best house plants. The late Peter Henderson on passing a plant of the P. utilis in the hall of his residence, remarked: " The best house plant I know of," and Mr. W. K. Harris observed to the writer a few years ago: " Yes, the best house plant there is, both of them, if they get water once a month only." "You mean once a week, Mr. H.?" "No, I don't. I mean once a month."
We have noticed ourselves plants of utilis in rooms far away from the light of the windows doing well if kept very dry. When growing fast they want plenty of water, but if you have to winter them in a cool greenhouse, say below 60 degrees, then be very sparing of water during the dark months.
They are undoubtedly two of the most satisfactory plants we can sell our customers.
From the fact that pandanus plants are natives of the tropics, a rather high temperature is required to secure the best results, a night temperature of 65 to 70 degrees being best adapted to their needs, and during the winter months little or no shading is needed, especially for the variegated species.
A good loam enriched with old manure forms a satisfactory soil, and as the plants make many coarse roots it is found best not to pot them too firmly, and during the summer to give an abundance of water. If grown in a moist atmosphere there is but little need for syringing overhead, and particularly during the winter an excess of water may lead to an attack of "spot," if coupled with an accidental low temperature at the same period.
Propagation is effected by means of cuttings of those species that sucker freely, and also by seeds. Where side shoots or suckers can be obtained there is but tittle difficulty in rooting them at any season, this operation being quickened (as in the case of a pineapple) by keeping the cuttings rather on the side of dryness until they are calloused, and by giving them a fair amount of bottom heat.
Seeds should be planted in light soil, and placed in a warm house, and the seeds should preferably be set with the bottom end up, this being the end from which the germs emerge. These seeds are a little peculiar, being closely set in a more or less globular mass that hangs down on a stout stem, while the individual seeds, or rather fruits, are compound, and often contain eight or ten germs, the latter being enclosed in cells of a tough, horny substance within the body of the fruit. Soaking of the seeds is sometimes resorted to prior to planting them, but I have not found any gain in rapidity of germination after soaking seeds of P. utilis for forty-eight hours in tepid water.
The most useful and most widely known species in cultivation at the present time are doubtless P. Veitchii and P. utilis, the first named being unquestionably among the best variegated plants for decorative purposes, while its endurance as a house plant depends largely on the conditions under which it has been grown, for soft and sappy specimens have an unfortunate habit of rotting off at times.
P. Veitchii has been in cultivation for the past thirty years, and has proved itself one of the most satisfactory introductions among foliage plants of the famous London firm whose name it bears.
The second species in importance in the trade is P. utilis, a species that has been in cultivation longer than the preceding, and is usually to be had in much greater quantities, owing to the readiness with which seeds may be obtained and germinated. This species, like P. Veitchii, is native in some of the South Sea islands, notably Madagascar and the island of Borneo, and on the latter island P. utilis is said to reach a height of sixty feet, forming a much branched tree.
The specific name of this pandanus, utilis, which signifies useful, seems to be especially applicable to the plant in Mauritius, where it is cultivated for its leaves, these being used in weaving the coarse matting from which sugar bags are made.
As a florist's plant P. utilis is most useful in small sizes, for example in pots of 4-inch to 8-inch sizes, there being but a limited demand for plants larger than these.
This species is a rapid grower, and requires generous treatment in regard to soil and watering, and gives but little trouble in its management, unless it may be in those cases where an outbreak of spot is developed. The latter trouble is caused by the burrowing of a minute insect in the tissues of the leaf, and its progress seems to be favored by over-watering. If plants become badly affected with this disease it is most profitable to throw them away at once, as they are likely to be permanently disfigured by it, but light attacks may be satisfactorily treated by keeping the plants somewhat drier and dosing them with sulphur.
P. candelabrum variegatum, perhaps more readily recognized under the name of P. Javanicus var., is another handsome variegated form, and a more recent introduction than P. Veitchii, having been introduced from Java in 1875. Our illustration indicates the very graceful habit of this plant, the leaves of which are narrow and pendulous, and grow to a length of three to six feet, the white variegation being very clear and sharply defined on the dark green ground color. Unfortunately this plant is very thoroughly armed, the leaves being edged with sharp spines, while the midrib possesses another line of spines which are turned the reverse way to those on the edges, thus making it almost impossible to handle the plant without getting caught.
P. candelabrum var. forms side growths freely even in a young state, and cuttings made from these growths root readily, but owing to its abundance of spines it has never become a very popular plant in the trade.
P. graminifolius is one of the small growing kinds that have been found useful to a limited extent in the trade, being at its best in a 4-inch or 5-inch pot, and only reaching a height of two to three feet when fully developed. This species is of tufted habit, being much branched, and having dark green leaves about half an inch wide, not so stiff as those of most of the species of pandanus, and armed with short whitish spines.
P. graminifolius is readily increased by means of cuttings, and in small plants may be considered among available stock for the centers of fern pans. The illustration has been prepared from a good photograph of this plant, and gives an excellent idea of its general character.
P. heterocarpus, also known as P. ornatus, is one of the handsomest of the green-leaved pandanuses, being a strong growing species with broad, dark green foliage, edged with whitish spines. The underside of the leaves of this species is lighter in color and slightly glaucous, a well grown plant forming a noble specimen.
P. heterocarpus is rather susceptible to overwatering during the winter, and in that case may develop spot, but with a little caution in that particular there is no special difficulty in its culture. I have never seen this species produce suckers, and it seems probable that the only means of increase is from seeds. P. heterocarpus is a native of the Philippine islands, from whence it was introduced about 1866.
P. reflexus is another notably handsome species, and though one of the oldest in cultivation is by no means common. This species produces very long and pendulous leaves, in a large specimen often growing five to six feet in length, dark green and shining and profusely armed with strong spines, those on the underside of the midrib being turned the opposite direction to those on the edges of the leaves, similarly to the arrangement of spines on P. candelabrum.
Pandanus Candelabrum Var. (Javanicus Var.)
The leaves of P. reflexus are so much recurved that they frequently hide the pot in a well-grown plant, and really have a very graceful effect, as will be readily seen from our illustration, but owing to its ever-ready armor of spines this plant is a most unpleasant one to handle, and is consequently not likely to become a popular one.
P. Vandermeechii is a comparatively rare species that would probably be useful in the trade if grown in quantity, being of somewhat similar character to P. utilis, but stouter in growth and usually more upright. The leaves of P. Vandermeechii are broad and stiff, dark green and slightly glaucous, the edges of the leaves and also the spines being dark red, and the same color appearing to some extent about the base of the leaves.
This species forms a very effective specimen, but does not appear to produce any suckers, and propagation must therefore depend on seeds. P. Vandermeechii was introduced from the island of Borneo, and is said to be peculiar to that island, though quite plentiful there.
Among novelties of the pandanus family that have been grown to some extent of late years are P. Baptistii and P. caricosus, but while both these species are attractive, neither is of much value commercially.
P. Baptistii is a rapid growing plant, the leaves of which are striped with yellowish variegation, and in some measure resembling the foliage of Phormium tenax var., but without the toughness of that plant.
P. caricosus is more dwarf in habit than the preceding, and has narrow green leaves that are but little armed with spines. It branches freely, and might be briefly described as a very strong P. graminifolius, though perhaps less useful than the latter for trade purposes.