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MYRTUS DISTICHA. 
, uf ry 5 Tete ‘~? ie ’ r F s : 
Nar. Orv. Myrtacex, Juss. Linn. Syst. Tcosandria Monogynia. 
MYRTUS, Lann., Juss. Cal. 4-5-partitus. Pet. 4-5. Stamina debilia, receptaculo angusto inserta. Ovarium 
2-3-loculare polyspermum : ovulis placente centrali insertis, Stigma simplex. Pericarpium baccatum, polysper- 
mum. ‘Testa tenuis. Embryo arcuatus, teres, cotyledonibus radicula duplo brevioribus. 
Sect. 2? Oxynruia. Stylus apice uncinatus. Semina angulata. mbryonis partes invicem conferruminate. 
Myrrtvs, pedunculis axillaribus multifloris foliis brevioribus, foliis distichis deflexis ovato-lanceolatis, ramis patentibus. 
Swarts Fl. Ind. Occ. 2. 894. 
Myrtus disticha. Swarts Prodr. 78. Willd. Sp. Pl. 6.971. Ait. Hort. Kew. ed. alt.3. 190. Sims, in Bot. Mag. 867, 
Myrtus horizontalis. Vent. Malm. 60. 3 
‘Descr. Suffrutex. Rami teretes, glabri, angulum feré rectum invicem efformantes, juniores leviter sericei. Folia opposita 
reflexa, subsessilia, oblongo-lanceolata, 3-nervia, venis transversis, inconspicuis subundulata ; juniora colorata. Pedunculi ax 
illares, multiflori. Calyx superus, 4-fidus, pilosus, resinoso-glandulosus, laciniis rotundatis ciliatis. Petala 4, subrotunda, 
sessilia, nunquam y.rarissimé expandentia, sed feré semper magis minusve conniventia et coherentia ; in tenerrimis annis adeo 
arcté coherentia ut non separanda. Stamina serie duplici inserta, indefinita. Anthera ovate incumpentes. Ovarium 2-loculare, 
polyspermum ; ovulis placente centrali insertis. Stylus rectus teres apice uncinatus. Stigma simplex. Pericarpium baccatum 
obovatum v. oblongum, atrum, purpureo-brunneum, calyce coronatum, uniloculare. Semina placente axili adherentia, 2-8, 
mutua pressione angulata, a carne libera. Testa tenera, carnosa, cinerea. Embryo exalbuminosus, carnosus, semini conformis, 
partibus omnibus invicem conferruminatis, vasculis resiniferis marginalibus perforatus. 
ae I RC 
Tt must be obyious to every one who has ever attended to the subject, that it is almost impossible to distinguish 
Myrtus and Hugenia trom each other by the characters hitherto attributed to them ; even when the fruit, on which 
their differences are chiefly said to depend, is within reach for examination. We conceive, however, that the difficult 
of which we have spoken, does not arise out of any want of characters in nature to distinguish these plants, which 
probably have as strict, if not stricter limits than those of most Natural Orders ; but rather from a laxness and incom- 
pleteness in the definitions of authors, who have introduced confusion among them by carelessly referring plants 
with all the characters of one genus to another ; and from each group having been crowded with species which differ 
as much from the genera in which they have been placed, as those genera do from each other. 
Their difference has hitherto depended entirely upon the fruit, as in fact it always must. We believe, however; 
it will be discovered that itis neither the pericarpium, nor the number of its cells, nor the number of the seeds, which 
will afford sufficient distinguishing characters ; but rather the structure of the ovarium as regards the placentation of 
its ovula, and the various modifications of embryo. 
_ Lf our ideas of the genus Myrtus are to be derived from the common Myrtle of the gardens, it will be characterized 
by a straight style, a 2-3-celled ovarium containing many ovula attached all round a thin central placenta, and b 
_ seeds with a slender arcuate embryo, of which the radicle 1s about twice as long as the cotyledons ; and all the species 
which differ from it in these respects will probably be referable to other genera. As there is, however, considerable 
difficulty in procuring specimens of the fruit of many Myriz in our herbaria, it is impossible at present to ascertain 
which really belong to Myrtus, properly speaking, and which do not. We may nevertheless observe, that in placen- 
tation M. tenuifolia, latifoha, and cerasina, agree with it ; and that the plant called M. Pimenta latifolia in the gar- 
dens has its ovula inserted in a similar way, but on a fungous placenta. 
As Myrtus disticha with the same sort of placentation has a hooked style, and seeds without any distinction of 
radicle and cotyledons, it may be advisable to consider it as the type of another genus, which may for the present 
stand as a section of Myrtus, and be called Olynthia, in allusion to its seeds. We cannot imagine how Ventenat 
could describe a cylindrical arcuate embryo in his M. horizontalis, which certainly is a synonym of this plant: we 
are confident he must have been in error, particularly as Dr. Sims’s observations upon the seed completely agree 
with ours. : Soe 
The Allspice plant of the West Indies was long ago considered a distinct genus by Dr. Solander, who has called 
it Myrcia in his Manuscripts. It has a straight style, a stigma somewhat capitate, an ovary with two cells, each con- 
taining a single ovulum hanging by its middle from the top of the dissepiment, its seeds solitary, with the organization 
of Myrtus. Myrcia being very near Myrsine in sound, we would propose that the specific be altered to a generic 
appellation, and that the plant be called Pamenra officinalis. ; 3 
There is still a third set of plants, consisting of M. crassifolia, montana, ramiflora, odora, splendens, and some 
others from the same quarter of the world, which have a straight style, and a 2- or 3-celled ovary, with ovula growing 
by pairs from near the base of the dissepiment, as in Pomacea. Undoubtedly these will constitute another genus 
when their fruit shall have been examined. From the appearance of the impregnated ovule, we should judge their 
seeds to be like those of Myrtus. M. tomentosa has the same structure of ovarium, but its habit is very different. 
Eugenia has exactly the same placentation as true Myrtus, but is distinguished by its very rigid stamens, which are 
quite different from the weak distorted ones of the other genera, and by its seeds (usually I or 2) having a Gras Cree 
oblong embryo with very large fleshy cotyledons, including within their base a small conical radicle ; and so differing 
from most other Myrtacee, justas Hriobotrya does from the rest of Pomacee. ‘ ennan 
We shall take some other opportunity of speaking of Suzygium, Calyptranthes, which has the seed of Hugenia, 
Greggia, and Caryophyllus. 
EXpLANATION OF THE PLATE. 
1. Flower-bud. 2. Flower. 3. Section of the same. 4. Transverse section ok the ovarium. ie Anthers. 7. Pollen. 
8. Top of the style and stigma. 9. Fruit. 10. Section of the same. Ii, Seed. 12, 13. Sestions of the same. 
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