GASTEROMYCETES 493 



parenchyma, such as we find in Hysterangium clathroides (H. stoloniferum 

 var. americanum) , the only species to be reported upon ontogenetically 

 (Rehsteiner, 1892; Fitzpatrick, 1913). In this species, the tramal plates 

 arise from the columella and anstomose in all directions (Fig. 315, 1 and 

 3). Where the hyphal palisade borders the glebal cavities it forms a 

 hymenium. The ends of the tramal plates next the peridium fuse with it 

 (Fig. 315, 2). At the proximal side of this zone, the tramal hyphae may 

 pierce the palisade in a tangential direction and approach the peridium 

 laterally. In this species the bulk of the peridium is composed of 

 pseudoparenchyma. 



In an undescribed species from California, the columella is very 

 thick and the ends of the tramal plates rarely reach the peridium, leaving 

 a single large cavity lined with a hymenium. The columella suggest a 

 pine cone projecting into the cavity. In another undescribed species 

 from the same region, the columella ends in a spherical knob in the center 

 of the fructification, from which radiate the primary tramal plates. 



From this point, the columella is percurrent and develops along two 

 diverging lines, one main line with the tramal plates continuing to develop 

 from the columella, the other with the tramal plates developing 

 increasingly from the top of the columella and the adjacent peridium, 

 suggesting the Agaricales in both ontogeny and final product. In this 

 latter line, which we will discuss first, the tramal plates disappear at 

 maturity } leaving the spores as a powdery mass within the dry peridium, 

 as in Endoptychum and Podaxis. The main line continues through 

 Rhopalog aster and Phallogaster to the Clathraceae and perhaps the 

 Phallaceae. 



In Secotium we have the counterpart of Elasmomyces and Macowan- 

 ites in the Hydnangiaceae. In fact these genera, along with several 

 other poorly known genera, are often included in a separate family, the 

 Secotiaceae. Conard (1915) and Gaumann (1926) regard this group as 

 an aberrant member of the Agaricales, modified by its hypogaeous habitat. 

 On the other hand, Loh wag (1924, 1927) and Cunningham (1925), following 

 the traditional viewpoint, consider this group as a family of the Gaster- 

 omycetes, forming the culmination of the Hymenogastraceous line. Seco- 

 tium is confined to S. Africa, Australia, New Zealand and the west coasts 

 of South and North America. The fructifications are fleshy and firm 

 and the gleba is never fragile and powdery, as in Endoptychum and 

 Podaxis. 



Both Secotium erythrocephalum and S. Novae-Zelandiae have been 

 studied ontogenetically (Cunningham, 1925), the latter in most detail. 

 Although most of the species of this genus are hypogaeous or epigaeous, 

 both these species are found on decaying wood in New Zealand. The 

 plants are gregarious, enabling one to find many developmental stages on 

 a single piece of wood. The first stage shows a furrow separating the stipe 



