Systematics and Evolution, Part A The Mycota

II. Ontogeny

The life cycle ofD. stillatus(Fig.13.1) is taken as
a representative example of the Dacrymycetes to
illustrate the most important developmental
stages. The morphology of basidiocarps
(Figs.13.2and13.5), however, is rather varied.
Usually, the hyphal context of the trama and the
subhymenium (Figs.13.1cand13.3a)isgelati-
nous due to the gelatinizing outer hyphal
walls and depends on the water content of the
fructifications. Hymenia are single-layered in
young stages and may develop into mutlilayered

thickening ones in older basidiocarps (Fig.13.1c).

A typical basidial ontogeny is illustrated in

Fig.13.1d. Only in rare cases are basidia three-

or one-sterigmate, the latter as inUnilacryma

unispora(Fig.13.8e). In most cases, mature basi-

diospores are transversely septate (Fig.13.1e)and

germinate with microconidia that appear to

reproduce by budding (Fig.13.1e), however lim-

ited in time and space. Spore germination with

hyphae, illustrated by Dacrymces palmatus

but also occurring inD. stillatus, is common,

and microconidia can develop on these haploid

hyphae (Fig.13.1g). Fragmented hyphae are also

Fig. 13.1Life cycle ofDacrymyces stillatus.(a)Basidio-
carps (b) Fructification with fragmenting hyphae (i).
(c) Detail of hymenium and subhymenium.(d) Basidial
ontogeny showing stages of nuclear divisions in
basidia. (e) Basidiospores and spore germination. (f)
Yeastlike budding of microconidia. (g) Spore germina-

tion with hyphae, illustrated from D. palmatus

but also occurring in D. stillatus.(h) Fragmented

hyphae producing microconidia. (i) Short-celled frag-

mentation of peripheral hyphae from anamorph fructi-

fication (b). Figures not to scale; from Oberwinkler

( 2012 )

358 F. Oberwinkler