Pacific Capsular 4.

The Complex: , Nani,

Pleurocalyptus, Purpureostemon

J.W. Dawson

Botany Department, University of Wellington, New Zealand

INTRODUCTION

four referred The closely related taxa consideredin this paper have all been to Metrosi- deros at some time.

Nani Adanson is still generally treated as a section of Metrosideros Banks ex Gaertn.

(nom. cons.) despite the objections of several earlier authors (Merrill, 1952; Rock, 1917;

of the Valeton, 1901; Miquel, 1885). A comparison description of Nani in the present paper with that of typical Metrosideros (Dawson, 1970) shows that the two genera differ

features. I with Merrill affinities of he widely in many agree (1952) that the Nani with

further revision Xanthostemon and suggest that a detailed at the specific level may lead to If then their being merged. such a merger takes place, Nani would have priority over the latter could be Xanthostemon, although a strong case for conservation of made. The validity of the separation of Pleurocalyptus and Purpureostemon from Xanthostemon will also need to be reconsidered.

COMBINED DESCRIPTION OF XANTHOSTEMON, NANI, PLEUROCALYPTUS,

AND PURPUREOSTEMON

Low shrubs to tall trees, mostly in tropical lowlands and lower mountain slopes from the Philippines to northern and ; branching predominantly monopodial; specialised bud scales wanting; leaves opposite or alternate, microphyllous and sometimes with to macrophyllous, dorsiventral; young parts mature parts a silvery or rusty tomentum. in sometimes leaf axils below dormant, abortive, vegetative apices, or rarely terminal(fig. 49); a simple (fig. 1) or compound (fig. 24) pleiochasium

flower. or reduced to 2 or 3 flowers (fig. 38) or to a single of linear bracteoles Lateral flowers with a pair (figs. 2, 38); terminal flowers usually ebracteate; hypanthium shallow and saucer-shaped (figs. 28, 53) to deep and cup-like

(figs. 5, 42); sepals 4 or 5, free (figs. 3, 26, 51) or rarely fused(fig. 39); petals* (figs. 4, 27, narrowed the least 41, 52) 4 or 5, free, to base, red, yellow, or white; stamens at times as long as petals, and at least four times their number, free, not grouped, usually in a whorl single from the hypanthial rim, sometimes in two whorls, rarely more, red, yellow,

*) The petals of some species (figs 41, 52) appear to be supplied with more than one vascular strand from

This the hypanthium. comesabout when the single leaf trace gives rise tolateral veins at or a little below the junction between petal and hypanthium.

315 316 BLUMEA VOL. XX, No. 2, 1972

Xanthostemon. — X. of inflorescence lowermost inflores- Figs 1—13. 1. paradoxus. Diagram group. Only dotted cence is shown in detail and in this the axes are actually obsolete. Black triangle represents the

dormant apex of the inflorescence bearingbranch; x 2/3. — 2—13. X. aurantiacum. — 2. Habit of flower with

stamens removed; x 2½. — 3. Sepal; x 3½ — 4. Petal; x 2½. — 5. L.S. flower. Ovules stippled within

not Dorsal view ovary, stamens fully elongated; x 2½ — 6. of anther; x 5. — 7. Side view of anther.

— 8. L.S. in — Pollen sacs toright; x 5. anther plane of connective, dorsal side to right; x 5. 9. T.S.

sacs T.S. anther. Pollen stippled, endothecium hatched; x 7. — 10. ovary. Ovules stippled: x 2½. — II.

T.S. Inner — L.S. Inner ovule. integument stippled; x 70. 12. ovule. integument stippled. Dotted line indicates eventual line ¦of separation of seed; x 70. — 13. Cell detail integuments and nucellus. Inner CANB WELTU integument stippled; x 240. (1: 53355; 2—13: 9587). W. Dawson: J. Pacific Capsular Myrtaceae 4 317

anthers with or white; (figs. 6—9, 29, 30, 43—46, 54, 55) an expanded, broadly convex

the of the a oil at the connective ensheathing upper part filament; single prominent gland of the connective sometimes smaller tip and a few to many glands elsewhere; filament anther dehiscence dorsifixed*, more or less versatile; longitudinal.

Ovary superior (fig. 5) to semi-inferior; 3 —5 locules, rarely 2 or 6; style as long as or

sometimes into the of the longer than the stamens, a little set top ovary; stigma small, flat the to convex; placentas extending across the locules to ovary wall and either: axile,

less in of the more or horizontal, and broad to narrow the vertical plane ovary (figs. 5, inserted the basal of the and 42) or: obliquely in angles locules, ascending to erect, narrow

(figs. 32, 57).

in around the shaft of the Ovules numerous, usually a single ring placenta (fig. 56) or when the latter forming an arc is erect, hemitropous (figs. 12, 32, 48, 57), laterally flattened,

sessile and fused with the placenta for most of theirlength; each integument two-layered

(fig. 13) with an increase in number oflayers towards the chalaza and micropyle; nuceflus

3- or 4-layered (fig. 13).

Hypanthium and sepals persistent in the fruit; capsule woody or coriaceous; placentas with the remaining in contact ovary wall (fig. 15) or becoming separated from it (figs. from hilum of the seeds 35, 60), distinctively striate the scars (figs. 14, 33, 59); seeds with greatly flattened laterally and more or less semi-circular; fertile seeds few the testa

formed from both integuments (figs. 18, 19); the outer layer of the outer integument of membranous the chalazal large tangentially elongated cells, rarely produced into a wing at end ofthe seed the (fig. 61); innerlayer of the outer integument ofmuch smaller more less of isodiametric cells each containing one to many prismatic crystals varying sizes; the the of outer layer of the inner integument thinwalled and colourless; inner layer the inner with of integument irregular wall thickenings and brown contents; a few layers within the of sterile derived nucellus tissue persistent testa; testa seeds probably from the

outer integument only, all cells empty and with heavily thickened walls (fig. 20). orbicular semi-orbicular face Embryo with broad, erect, to cotyledons lying to face

bent more or less at to the and (figs. 21—23, 37> 63); hypocotyl right angles cotyledons

lying adjacent to the hilum, hypocotyl sheath wanting.

COMPARATIVE REVIEW OF THE FOUR GENERA

I. Xanthostemon F. v. M., W. J. Hooker’s J. Bot. and Kew Gard. Misc. 9 (1857) 17- leaves Shrubs or trees; alternate, microphyllous to macrophyllous. Inflorescence an

axillary simple pleiochasium or reduced to a few flowers or a single flower. Hypanthium shallow to deep; sepals free. Ovary superior to semi-inferior; placentas axile, broad or Seeds narrow, more or less horizontal; ovules forming a complete ring. not winged. and of Distribution: Australia: 6 species in tropical parts Northern

Territory and . They include the type species .

New Caledonia: about 35 species (according to Guillaumin, 1948, but this estimate is Solomon Islands identified. probably too high). (Santa Ysabel): one species not yet : 3 species. Celebes: 1 species. Philippines: 4 species.

is *) The correct term here difficult to determine. Mueller (1857) described the anthers as basifixed and

dorsifixed. The filaments do be inserted the base of the Gugerli (1940) as appear to at or near connective,

but the two anther lobes extend below the point of insertion and are usually narrowly fused for a short

distance (fig. 8). 318 BLUMEA VOL. XX, No. 2, 1972

2. Nani Adanson, Fam. Pl. 2 (1763) 88.

leaves Shrubs or trees; opposite, mesophyllous. Inflorescence an axillary simple or com- pound pleiochasium. Hypanthium shallow, sepals free. Ovary more or less superior; inserted placentas obliquely in basal angles of locules, narrow, more or less vertical; ring is of ovules interrupted where placenta in contact with the ovary axis. Seeds not winged. Amboina: Celebes?: Distribution: I species (this is the type species, N. vera).

Close to and described from cultivation the 1 species (N. petiolata. N. vera a in in Botanic have the Bogor Garden, which Merrill, 1952, suggests may come from Celebes). Guinea: At known Xanthostemon crenulatus. Australia New 1 species. present as (Arnhem

Land): 1 species at present known as Metrosideros eucalyptoides.

Comment: From the foregoing descriptions based on the type species of the genera it that Xanthostemon F. M. and Nani Adanson be the appears v. can distinguished by former having alternate leaves and axile, horizontal placentas and the latter opposite leaves and obliquely inserted erect placentas. However, X. oppositifolius of southeast

Queensland and an unidentified specimen from Western New Guinea (CANB 89639) have opposite leaves and horizontal placentas. Thus, on present knowledge, the separation feature leaf be based — of the 2 genera can on only one arrangement or placenta angle.

Xanthostemon. — — fruit with of and Figs 14—23. 14—20. X. aurantiacum. 14. Empty part hypanthium

undehisced X — capsule cut away; X 2½. — 15. L.S. undehisced fruit; X 2½. — 16. T.S. fruit; 2½. 17.

Fertile seed; X 3½. —18. T.S. fertile seed. Inner integumentand cotyledons stippled; X 20.— 19. Cell detail

— sterile seed; T.S. testa fertile seed. Inner integumentand crystals stippled; x 240. 20.Cell detail T.S. testa

X 240. — 21. X. macrophyllum. Embryo; X 7. — 22.X. aurantiacum. Embryo; X 7. — 23. X. aurantiacum.

Cotyledon from seedling; X 3½. (14—20, 22, 23: WELTU 9587; 21: McKee 20409). W. Dawson: J. Pacific Capsular Myrtaceae 4 319

Bull. 3. Pleurocalyptus Brongn. & Gris, Soc. Bot. Fr. 14 (1867) 264.

Small tree; leaves alternate, mesophyllous. Inflorescences axillary, 3-flowered. Hypanthium

the remains deep, sepals completely fused, calyx separating irregularly as a cap which the flower. attached at one side of Ovary more or less superior; placentas axile, broad,

horizontal; ovules forming a complete ring. Seeds not winged.

Distribution: New Caledonia: 1 species (P. deplanchei).

Comment: The only difference from Xanthostemon is the fused calyx.

4. Purpureostemon Gugerli, Fedde’s Rep. 46 (1939) 228.

Small shrub; leaves alternate, microphyllous. Inflorescence a terminalsimple pleiochasium. inserted Hypanthium shallow, sepals free. Ovary more or less superior; placentas obliquely in of basal angles locules, narrow, diagonal; ovules forming a complete ring. Fertile seeds

with a broad membranous wing at the chalazal end.

Distribution: New Caledonia: 1 species (P. ciliatum).

Comment: Similar to Nani in the insertion of the placenta, but differing in having alternate leaves and a complete ring of ovules. Differs all three other inflorescences and from genera in having terminal winged fertile seeds.

Nani — is Figs 24—37. vera. 24. Diagram of inflorescence group. Only lowermost inflorescence shown

in detail. Black the dormant of the inflorescence — triangle represents apex bearing branch; X 2/3. 25. Habit

stamens — 26. L.S. offlower with removed; x 2½. Sepal; X 2½. — 27. Petal; X 2½. — 28. flower. Ovules stippled within ovary; X 2½. — 29. Dorsal view ofanther; X 10.— 30. L.S. anther in plane ofconnective;

X — X — L.S. dorsal side to left; 10. 31. T.S. ovary, 2½. 32. part of ovary. Ovule stippled; X 15. — 33.

Empty fruit; X 2½. — 34. T.S. undehisced fruit. Fertile seeds stippled; X 2½. — 35. L.S. undehisced fruit;

— — L X 2½. 36. Fertile seed; X 2½. 37. Embryo; X 7. (24—37: 898.206—728). BLUMEA VOL. 320 XX, No. 2, 1972

Figs 38—48. Pleurocalyptus deplanchei. — 38. Inflorescence with flower buds; x 2½. — 39. Flower bud

with — flower. still attached sepal operculum beginning to separate; x 2½. 40. Opening Sepal operculum

— — L.S. in on lower right side; x 2½ 41. Petal; x 2½. 42. opening flower. Ovules stippled ovary; x 2½.

—43. Side view of anther. Dorsal side to right; x 5.—44. L.S. anther in plane of connective. Dorsal side

— Dorsal view — T.S. anther. to right; x 5. 45. of anther; x 5. 46. Pollen sacs stippled. Endothecium T.S. — Ovules — L.S. ovule. hatched; x 10. 47. ovary. stippled; x 2½. 48. Inner integument stippled. Dotted McKee line indicates eventual line of separation of seed; x 70. (all: 19203). W. Dawson: J. Pacific Capsular Myrtaceae 4 321

ciliatum. — of terminal inflorescence. Dotted Figs 49—63. Purpureostemon 49. Diagram axes actually

obsolete; X 2/3. — 50. Habit of flower from below. Stamens removed; X 2½. — 51. Sepal; X 2½. — 52.

Petal; x 2½. — 53. L.S. flower. Ovules stippled in ovary; X I. — 54. Dorsal view anther; X 8. — 55. L.S.

in 8. — End view anther plane of connective. Dorsal side to left; X 56. ofplacenta with ring of ovules;

— L.S. of Ovules — L.S. ovule. Dotted X 15. 57. part ovary. stippled; X 15. 58. Inner integumentstippled.

line indicates — eventual line of separation of seed; X 70. 59. Empty fruit with part of capsule cut away;

X 3½ — 60. L.S. undehisced fruit; X 3½. — 61. Fertile seed. Vascular bundle is visible in the wing; X 2½. —

62. Sterile — seed; X 2½. 63. Embryo; X 7. (all: Veillon 1814). VOL. 322 BLUMEA XX, No. 2, 1972

DISCUSSION

The reviewed here differ from Metrosideros features genera in so many that their retentionin the subtribe Metrosiderinae can hardly be justified. In fact, they do not seem to fit of the subtribes. of the readily into any currently recognized Some features which

them from Metrosideros are shared with the subtribe — distinguish Eucalyptinae e.g. broad in the — subtribe crystal layer testa; cotyledons but they differ from that in many other anther respects, e.g. pleiochasial inflorescences, expanded connectives, protruding each and sheath placentas, no ovulodes, cotyledons not enfolding other, no hypocotyl in the embryo.

ACKNOWLEDGEMENTS

I Dr. H. S. McKee am grateful to and the Botanical Section of ORSTOM in Noumea for supplying and field specimens assisting with work, to Professor C. G. G. J. van Steenis for the loan of herbarium

D. specimens of Natti vera, and to Professor H. Gordon for his helpful comments on the manuscript.

REFERENCES

W. 18: DAWSON, J. 1970. Blumea 441 —445. K. GUGERLI, 1940. Monographic der Myrtaceengattung Xanthostemon. Zurich: 22.

A. Paris: GUILLAUMIN, 1948. Flore analytique et synoptique de la Nouvelle Caledonie. Phanerogames. 231. E. D. MERRILL, 1952. J. Arn. Arb. 33: 156.

F. A. I: MIQUEL, W. 1885. FL. Ind. Batav. 399.

MUELLER, F. VON. 1857. W. J. Hooker's Journ. Bot. and Kew Gard. Misc. 9: 17.

For. T. H. ROCK, J. F. 1917. Board of Agric. and Bull. 4: 10.

VALETON, TH. 1 901. Ic. Bogor 1 (Suppl.): 65.