112 FLORA VITIENSIS. 
Systematic botanists who have dealt with the whole vegetable kingdom have been as unsuccessful in 
finding distinctive characters for the two Orders as our local botanists, and the confusion that is thus 
caused in general systematic works’ is embarrassing. After the grave errors introduced into the ordinal 
characters of Hederace: by Don, and copied by Bartling and De Candolle, had been corrected by Brown 
and Bennett in ‘ Plante Javanice,’ it became evident that Umbellifere and Hederaces were not so distinct 
as had been supposed by botanists labouring under the belief that Don’s errors were the result of true 
observations. Lindley, in his ‘ Vegetable Kingdom,’ makes the following distinctions between the two 
Orders :— 
** Umbellifere. Fruit didymous, with a double epigynous disk. 
“ Hederacee. Fruit not didymous, without a double epigynous disk, 3- or more celled. Pentamerous 
flowers. Corolla valvate. Leaves alternating, without stipules.” 
The principal distinctive characters here relied upon (the didymous or non-didymous fruit and the pre- 
sence or absence of the double epigynous disk) do nòt stand the test of practical application. About one- 
half of all known Hederaceze have a didymous fruit, and in many Umbellifere the disk is not double'if the 
styles are closely united, there being in that instance only one disk, as is the case in most Hederacesm. The 
pentamerous flowers are general in both Orders, tetramerous ones forming the exceptions. Alternate leaves 
are also a feature common to both Orders, opposite ones being again the exception. Stipules cannot be 
denied to many Hederacew, being, for instance, highly developed in Tetrapanax papyrifera, C. Koch, the 
rice-paper plant. 
Unless some additional characters besides those derivable from the sstivation of the corolla can be 
found, it will scarcely be possible to make Hederacez more than a suborder of Umbellifere. The general 
name of Umbellifere might be retained for the whole Order, whilst that of Apiaces (following Lindley) 
might be adopted for one suborder and Hederaces for the other. The two suborders would occupy the 
same relative position as do Clematidee and Anemones in Ranunculacez, and Papilionacez, Cæsalpineæ, 
and Mimoses in Leguminose, all of which are distinguished by the estivation. However, when the whole 
genera belonging here shall have been carefully examined, it may become necessary to establish even more 
suborders. In Trachymene caerulea (Didiscus, Hook.) and most genera with irregular corollas, the petals 
are vexillary in bud, exactly as they are in Papilionacew ; in Aralia racemosa, Stilbocarpa polaris, and a few 
others, the estivation of the corolla is quincuncial. Both being different degrees of imbrication, we may, 
in the present stage of the inquiry, rest content with two suborders of Umbelliferze being defined :— * 
l. Apiacee. Corolla variously imbricate in estivation. 
2. Hederacee. Corolla valvate in æstivation. 
I prefer the name Hederacew because it is not an innovation; Hedera Helix is a widely-diffused and 
very characteristic plant of the Order, and the few typical species at present retained in Aralia, havimg a 
quincuncial corolla, must be shifted to Apiacee, ; 
In many, but by no means in all Apiaceæ, the carpels separate mechanically from the carpopods. In- 
Hederace the carpels also separate occasionally, but there are never any thread-like carpopods. So it may 
be stated that all Umbelliferz with separating carpels and distinct carpopods are genuine Apiaceæ, but that 
not all Apiaceæ have separating carpels and distinct carpopods. But the systematic value of the carpopod 
or earpophorum is depreciated by the recent observations of Von Mohl, which tend to show that the carpo- 
phorum is not a distinct organ, but part and parcel of the carpels.* 
I may add that Corne: are chiefly distinguished from Hederacez, according to most authors, by their 
tetramerous flowers and opposite leaves. But there are Cornes with pentamerous flowers, for instance, 
Griselina and Corokia; and Cornus alternifolius, Linn., is a familiar instance of alternate leaves. Corneze 
agree in every respect with Hederacew, except that, as the younger Agardh has pointed out, Hederaceæ, 
like Apiaees, have epitropous ovules, and Corner apotropous (Gemmule “sunt nempe in Araliaceis et 
Umbelliferis velut in Hamamelideis epitropz, in Cornaceis vero (observavi gemmulas Corni, Benthamia, 
Corokie et his proxime Awcube) ut in Caprifoliaceis et Viburneis apotrope.” J. G. Agardh, Theoria Syst. 
Plant. p. 303).— For a series of papers on Hederacee consult Seem. Journ. of Botany, vol. i-iii. 
I. Hydrocotyle, Tournef. Inst. t. 173. Pedicelli inarticulati. Flores ecalyculati, herma- 
* “The different views [taken of the nature of the carpophorum of Umbellifere] are contradicted by 
a microscopic examination of the fruit, yielding as it does the result that a carpophorum distinct from the 
carpels and joined to them by accretion does not exist, but that it forms really a part of the carpels them- . 
selves, and, when the fruit is ripe, separates from them, and then only becomes apparently a separate organ. 
This upsets all the speculations as to whether the carpophorum is to be regarded as an axial formation 
or (as De Candolle explains it) as the petiole of the carpellary leaf. The true state of the case becomes 
evident if in different heights of the unripe fruit transverse sections are made, and these be compared 
with vertical ones."—Hugo von Mohl, “On the Carpophorum of Umbellifers," Bot. Zeitung, vol. xxi, 
(1863) p. 264. 
