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Telopea Vol. 6(4): 1996 
the maioritv of species of Epilobium and Fuchsia are characterized by its atisence_ 
Sow'ver we have confirmed Ihe presence of a hypostase i.r al spec.es examined of 
EpZium and Fncte/a, as well as in fhe other genera for wh.ch mfyma m,, on the 
hypostase has not been available earlier. It appears, therefore, to be common to 
species of Onagraceae. 
Fertilization, endosperm and embryo (Table 4): Furtigation is porogainom 
Johansen (1934) reports irregularities with respect to the path of f ® 
of Circaea alpina subsp. pacifica. but we were not able to confirm his f sejva t ons in the 
material of tliis taxon that we examined. Endosperm formation is 
(Fig. 22). The endosperm is scanty throughout the process of seed development bvei 
in a nearly mature seed, a limited amount of cellularized 
periphery of the embryo sac and particularly on the chalazal side (Fig 28). The mahire 
Led^coSpletely lacks'endosperm (e.g., in Fuchsia, Fig. 23, and Cougijlocai pus, Fig. ). 
Earlier, the Onagrad type of embryogeny has been reported 
(Soueees 1946), Oenothera (Soueges 1920), Chamerion (Lebegue 1948b) and Eptlobn n 
(Leb^ue 1948a). We observed the Onagrad type in Cayopinjtum hunnle w 
ovata and Clarkia heteraudra. The embryo in a mature seed is straight and 
dicotyledonous with a short suspensor (Fig. 26). 
Seed appendage and seed coat (Table 4): Except in Hauya, Xylonagra, 
EpilobiL, the seeds of Onagraceae have no conspicuous ^PP^"f‘"Ses. ®oth 
and Xylonagra have a wing on the chalazal side. The wing is flat along the axis o 
raphe to antiraphe. All species of Chamerion and all but a few species of 
(especially species of the former Boisduvalia) have a coma on the chalazal end of the 
seed that is composed of a tuft of unicellular trichomes. 
The mature seed coat basically comprises the exotesta, endotesta, exotegmen and 
endotegmen. In addition, a mesotesta is present in Fuchsia (Figs 23,24), Circata ,(Fig^25 , 
Lopezia Oenothera (some species only) and Stenosiphon (Tobe Wagner & Chin 1987), 
whereas Gongylocarpus (Figs 26, 27), Xylonagra (Figs 28, 29) and all other genera lack a 
mesotesta. As mentioned previously, we did not examme the variation of coat 
structure within particular genera, which is often extensive, for the purposes of fliis 
paper. The following are common features characteristic of the whole family. The 
endotesta, which may be relatively less conspicuous in some species of various genera 
than usual for the family, is crystaliferous, and its cells are vanously thick-walled, he 
exotegmen is composed of longitudinally elongate fibrous (or tracjeoidal) celb; the 
endotegmen comprises longitudinally elongate, tanniniferous cells. Carlquist & ^ven 
(1966) described the seed coat histology of Gongylocarpus rubricauUs as entirely cAff^en 
from that of G. fruticulosus, but we found them to be similar (G. rubneauhs. Fig. 27); both 
species share a crystaliferous endotesta and a fibrous exotegmen. 
Discussion 
In 1983, on the basis of the limited information then available, we discussed the 
relationships of Onagraceae with the other families of the order Myrtales. We concluded 
that 'none of the embryological attributes of Onagraceae suggests a particular relationship 
either to Lythraceae or to any other family' (Tobe & Raven 1983: 86-87). As a result of 
our subsequent studies, (see Tables 2-4; Tobe & Raven 1986b), however, we have 
confirmed that most embryological features such as the Oenothera type embryo sac, are 
common to the entire family Onagraceae. With respect to the relationships of the family, 
we offer the following observations. First, the Oenothera type embryo sac distin^ishes 
Onagraceae from all other myrtalean families. Second, the presence of the multi-celled 
ovule archesporium (except in Ludwigia), as well as the presence of starch grains m the 
