670 
Telopea Vol. 6(4); 1996 
Table 1 (continued). 
Species 
0. villosa Thunb. 
subsp. villosa 
Stenosiphon linifolius 
(Nutt.) Heynhold 
Oarkia dudleyana (Abrams) 
J. F. Macbr. 
C heterandra (Torrey) 
H. Lewis & Raven 
[Syn: Heterogaura heterandra 
(Torrey) Cav,] 
C. tenella (Cav.) Lewis & 
Lewis subsp. tenella 
Collection 
U.S.A., Missouri, St. Louis Co., Wagner, Mill, 
a Tobe 4519 (MO) 
U.S.A., Oklahoma, McClain Co., Sullivan 
1038 (OKL) 
U.S.A., California, Gottlieb 129 
U.S.A., California, Tuolumne Co., Gottlieb 
in 1977 (MO) 
Chile, Malleco, Curacao, Marticorena a 
Ovezada 1669 (MO) 
Parts examined 
Anthers Ovules Seeds 
+ 
+ + 
+ + 
+ + 
+ 
+ 
+ 
Tribe Epilobieae 
Epilobium canum (Greene) 
Raven subsp. canum 
E. dliatum Raf. subsp. 
watsonii (Barbey) Hoch 
& Raven 
E. condnnum (D. Don) 
Hoch & Raven 
[Syn: Boisduvalia subulata 
(Ruiz & Pavbn) Raimann] 
E. pygmaeum (Speg.) 
Hoch & Raven 
[Syn: Boisduvalia glabella 
(Nutt.) Walp.] 
Cult., Univ. Calif. Bot. Gard. (Berkeley), 
UCBG 58.996 (UC) 
U.S.A., California, Marin Co., Sharp in 1967 
(MO) 
Chile, Nuble, Cheese a Watson 4405 (K) 
U.S.A., California, Yolo Co., Crampton 9212 
(MO) (+) 
+ 
+ 
Results 
Most embryological characters examined were constant within the entire family 
(Tables 2-4). In these tables, features reported earlier are indicated with an asterisk 
(*); all other features are reported here for the first time. All features mentioned in 
the following discussion are common to the entire family, as far as known, unless 
differences between genera and species are mentioned specifically. 
Anthers and microspores (Table 2): In general, the anther wall varies from five to 
six cell-layers thick, but it is often three or four cell-layers thick in Gayophijtuni and 
four cell-layers thick in Clarkia heterandra. The anther wall is basically composed of 
an epidermis, an endothecium, two or three middle layers and a tapetum. In most 
genera the middle layers share their histogenetic origin with both the endothecial 
and the tapetal cells (i.e., Basic type; Fig. 1), although both or either of the middle 
layers may be lacking in Gayophytum. However, in Hauya, Calyhphus, Gaura and 
Clarkia, the middle layers have a'common histogenetic origin with the tapetal cell 
(i.e., Monocotyledonous type; Fig. 2). In Calylophiis and Gaura, the Basic type also 
occasionally occurs, but it is not the predominant condition. 
As the anther develops, the middle layers are completely crushed. The epidermis is 
basically persistent until the time of anther dehiscence, although it may collapse 
locally. The endothecium always develops fibrous thickenings. The tapetum is 
glandular and its cells become two-nucleate. We did not see any tapetal cells with 
more than three nuclei in the species we examined, although Geerts (1909) has 
reported two- to four-nucleate tapetal cells in Oenothera glazioviana CO. lamarckiana'). 
Meiosis in the microspore mother cells was accompanied by simultaneous cytokinesis 
in the material we examined. The arrangement of microspores in a tetrad is mostly 
