96 PRINCIPES [Vol. 2 Viabilityof PalmSeeds. Nrr J. Dr Lnox

In any discussion of palms, the sub- for this group which includesAcrocomia, ject of viability of seedsis an important Archon,tophoenix, Arecastrum, Arikury' one. To be able to grow and appreciate roba, Attalea, Borassus,Brahea, Cham- palrns,.we must in most instancesstart aerops,Coccothrinax, Colpothrinax, Co- from .Many failures of germination pennicia,Dietyos perma, Elaeis, Erythea, have been attributed to poor practices, H oweia, H yphaene, Iubaea, M ascarena, but if we could trace the circumstances Nan,norho p s, Op siandra, Orbigny a, Pau' under which the were collected rotis, Phoenix, Pseud,ophoenix, Rhapis, and sent, we would find that the seeds Sabal, Scheelea,Serenoa, Syagrus, Thri- had passedtheir period of viability in nax, Trachycarpus, and Trithrinax, It transit so could not have germinated should be erpected that as seedsbecome anyway. An understandingo{ the viabil- older there will be a proportionate de- ity of seeds,therefore, will greatly im- creasein germination. prove chanceso{ obtaining germination. Palms from those parts of the tropics A palm seedhas a thin seedcoat with- where changesin temperature and rain- in which lies an , the young fall are slight and palms from low body, and the endosperm or albumen swampy areas bear seedsthat are very upon which the embryo feeds until it can short-lived, remaining viable from two absorb nutrients through its own de- to three weeks. Here the decrease in veloping root system. It is unlike many germination falls ofi sharply toward the dicotyledonous seeds which go into a maximum length of time. Generaknown state of dormancy until conditions are in this classinclude Actinorhytis, Areca, favorable for germination. Instead, the Balaha, Bentinckia, Bismarckia, Calyp' embryo of the palm seed, which is al- tr ocaly x, Caly ptr onoma, Chamb ey r onia, ways next to the thin surrounding seed Clinostigma, Cyrtostachys, Di'd'ymos- coat, begins to shrink and dry up when pertna, Drymophloeus, Eugeissona,Eu' conditions are unfavorable. It is the terpe, Gronophyllum,, I guanura, Iriartea, length of time required to complete this ! essenia.,Lino spad,ix(Brcularia), Lo'xo- shrinking process with which we are cocctls, Mauritia, Metroxyl'on, Nenga, concerned-Jhe longest period that can N ormanbya, Nypa, Oenocarpus,Oncos' safely elapse between maturation and perrrla' Orania, Pinanga, Podococcus, planting of the seed. Ptychoraphis, Raphia, Rhopaloblaste, Exact time periods are difficult to Roscheria, Salacca, Socratea, Steaen- give becauseof many variable factors. sonia, Veitchia,, Verschalleltia and, Wet- Several general rules, however, can be tinia. Seedsof these genera give us the applied to palm seeds. Those coming most germination trouble. from palms of sub-tropical areas, from There is, however, an intermediate areas having distinct hot and cool sea- classof palms from tropical areas.These sons or wet and dry seasons,and seods palms bear seedswhich remain viable with thick endocarp remain viable for for about four to six weeks. Genera of sometime. Two to three months is usual intermediatenature arc Aiphanes, Aren- Astrocaryum, Ba'ctriso Caryota, *Presented at the Palm Conference, Fairchild &d, Chrysalidocarpus, Corry" Tropical Garden, April 18, 1958. Chanaeilorea, r95Bl DE LEON: YIABILITY pha, Cryosophila, Diplothemiurn, Geo- shipped. It doesnot apply where efforts nornao Heterospathe, Latania, Licuala, are made to prolong viability by protect- Liu istona, P hy telepha s, P ritchard,ia, P ty - ing seed from the drying effects of air. chosper ma, Reinhardtia, Rhopalostylis, The material most frequently used for protection dry peat-moss. The prac- Roystoned,, and, Synechanthus. is tice at the Botanic Gardens,Singapore, Most of the species within a for a long time has been to pack palm react in a like manner, In genera where seedsin dry peat-moss.enilosed in.small there are a great many species we may tins and send by sea mail. Sometimes expect exceptionsto the rules. Thus we the seeds germinate enroute and the find that Pinanga Kuhlii seedsremain young sprouts die due to lack of mois- viable longer than those of most species. ture, but seedsof evensome of the short- We also find that seed of Chamaeilorea est-livedpalms such as Pinanga may be erumpensremains viable longer than its receivedin good condition after eight to intermediaterange would suggest. ten weeksin transit. Germination is usu- There are several palm genera that ally thirty to fifty percent. The late Dr. have never been introduced into cultiva- David Fairchild, when on his expedition tion in the United States, but we can to the East Indies, sent seedspacked in safely predict the viability of their seeds peat-mossby air. Though air transporta- by the areas from which they come and tion was less highly developedthan it by their relationship to other genera. is today, seedsof many of his rare palms Thus seeds oI Prestoea, which have not germinated. been introduced, should be short-lived When good air transportation is avail- since the genus is closely allied to Ea- able seedsmay be picked fresh and sent terpe, Iessenia, and, Oenocarpus. direct by airmail without packing ma- It is interesting to note, in going over terial. Unless unduly delayed, such lists of palms that have long been culti- seed should germinate. When delays vated in South Florida, that nearly all in shipping are expected or when air of the speciesthat are well established facilities are not well established,seeds belong to genera in the long and inter- should still be packed in dry peat-moss mediate classesof viability. The rea- soon after collection.despitethe added sons are rather apparent, for during the effort and expense. days of active seed introduction air should be sown as soon after transportation was in its infancy and Seeds costswere prohibitive. This same situa- collectionas possibleto obtain tlre fastest tion revealsitself in other tropical botan- possible germination. The older the ical gardens. When great distanceshad seed, the longer it takes to germinate, to be crossed,only those seedscapable providing it is still viable. In old seeds of remaining viable for sometime germi- the shrinking of the embryo has already nated. Nowadays, with good air trans- begun. It therefore takes extra time for portation reaching many areas of the the embryo to absorb water and regain world, we have been able to obtain good its original proportions. Last year, the seedsoI many palms in the short-lived Fairchild Tropical Garden received a group. shipment of Arenga pinnata seeds col- The aboveinformation appliesto seeds lected in Cuba. The seeds were quite handled in the custom,arymanner; that fresh and germinatedwithin two months. is cleaned, placed in a container, and At the sametime, I receivedseeds of this 9B PRINCIPES [Vol. 2 palm from North Borneo. There was an months in sub-tropical areasunless they interval of five weeks between the date are placedin a glasshouseor other means of collection and the date of receipt. Be- of applying warmth are used. They will, fore sowing, some of the were however, remain viable until spring if examined. They had already begun to the germinating mediuin is kept slightly shrink. The actual time of germination moist. Too much moisture will cause with the addition of bottom heat was six seedsto rot. months. At one month intervals, some It is hoped that the information given of the embryos were again checked.By here will be of some use to anyone at- the fourth month, they appeared to be tempting to grow palms {rom seed. The well proportioned and filled the cavity importance of the short period of via- again. bility should be impressed on the col- Although viable, seedsof most palms lector and shipper by those personswho will not germinate during the winter seek foreign sourcesof seed.

The Preparationand Germination Of PalmSeeds. H. F. Loovrrs

Among the severalthousands of p,alm fore arrival at their destinationhas much speciesonly the coconut, date and Afri- to do with the results obtained after can oil palm have great commercial im' planting. portance. Several other species are o{ _ The three factors most injurious to minor value, while the majority of palms palm seeds up to the time they are are planted as ornamentalsor for their planted are (1) extreme drying out, botanical interest. Little has been writ- causing the embryos to shrivel and re- ten on the preparation and germination ducing viability in proportion; (2) the o{ palm seedsin general; most references formation of surface molds, many of relate to those few speciescultivated for which seem able to penetrate readily to their commercial products. While much the embryos and affect their viability; can be learned from these papers it is and (3) excessiveage. Under the best the vast group of non-commercialpalms conditions most palm seeds are short- that holds most of our interest. lived, severalmonths at most, and seeds Naturally, the ideal palm seed for obtained from individuals or institutions planting is that from fully ripe , who make a practice of drawing them planted within severaldays of harvesting from stored bulk collections should be under conditions that will induce rapid under suspicion. Cutting through the germination. However, these conditioni seed coat and examining the embryos are not always attainable, for thq seeds to see if they are greatly shrunken or of many specieshave to be shipped great discolored from the white to creamy- distances,and the care they receive be- white seen in viable seedsmay make it possibleto avoid the planting and long *Presented at the Palm Conference, Fairchild Tropical Garden, April 18, 1958. care of worthless samples.