Acrochaetium subseriatum Børgesen

Acrochaetium subseriatum£>oe//gs., sp. nov. ; A. seriato Boergs.
proximum, quod tamen thallo robustiore et cellulis brevioribus a
specie nostra distinguitur.
Thallus caespitosus, usque ad i mm. altus, e hlamentis brevibus
irregulariter ramosis in thallo hospitis repentibus surgens et e
filamentis erectis ramosis compositus. Fila erecta in basi plus minus
quoquoversum, in superiore parte unilateraliter ramosa, e cellulis
cylindricis interne 27 [x longis, 5-8 ¡a latis, medio 35 ¡a longis,
4-6 ¡a latis, composita ; chromatophorum parietale, pyrenoide
laterali instructum. Sporangia oblongo-ovata, 11-12 ¡a longa et
6-7 ¡a. lata, sessilia aut raro pedicellata, ad basin ramorum seriatim
orta.
India : Tuticorin, in Chondria sp. epiphytica, Boergesen 5710
(type).
This plant (Fig. 6) is found upon Chondria armata Okarn. var.
plmnaris (described in this paper). It forms dense, very branched
tufts, about 1 mm. high. The base consists of short, irregularly
ramified, creeping filaments composed of short cells (Fig. 6b). These
filaments are probably partly immersed in the cuticle of the host
13«.PC. 3. I
Fig. 6. Acrochaetium subseriatum Boergs. a, upper part of the thallus
with sporangia ( X 150). b, basal part of a plant ( x 350).
Il8
CllVlScl exsurgll. 1 nciLL'l'ia usque x ill. anus, tuiuic iuuiu-puipmcus,
in thalli adultiore feminei forminibus numerosissimis minimis
119
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