Comminutispora agavacearum A.W. Ramaley [as ‘agavaciensis‘], Mycologia 88(1): 133 (1996)

Index Fungorum Number: IF 414805; Facesoffungi Number: FoF 11100

Ascomata (Fig. 1) immersed, separate, unilocular, brown, sphaeroid to oblong, the top flattened against and adherent to the host epidermis, 100-200 μm long, 85-150 μm wide, 75-125 μm tall, a small cylindric papilla penetrating the host epidermis. Wall 16-32 μm thick at the bottom and sides, thicker at the top, composed of 3-7 layers of brown-walled cells, the outer layers darker and thicker-walled, lighter toward the interior. Asci (Fig. 2) oblong, 76-100 x 16-24 μm, bitunicate, basal, 8-spored. Pseudoparaphyses lacking, interascal cells often plentiful even at maturity; ostiolar channel periphysate. Ascospores (Fig. 3) obovoid or clavate, the apex bluntly rounded, tapered toward the base, 20.8-30.4 x 7.2-10.4 μm, transversely 15-septate, the first septum approximately median or somewhat supramedian, a longitudinal septum dividing all or some of the cells, with additional longitudinal, transverse and oblique septa, hyaline, smooth, thin-walled, lacking a gel coating, ultimately forming tiny secondary ascospores within the ascospores. Secondary ascospores (Fig. 3) bacillar, allantoid, or irregularly shaped, mostly 1.6-3.2 x 1.0-2.4 μm, smooth, hyaline, liberated into the ascus.

Holotype – U.S.A. Texas: Brewster Co., Big Bend National Park, ca 60 m above the saddle between the points immediately across the road from and above the Lost Mine Trailhead, in dead leaves of Dasylirion leiophyllum Engelm., 25 Oct. 1994, Annette Ramaley 9445 (BPI 802958).

Paratypes – U.S.A. New Mexico: Lincoln Co., Valley of Fires, mile 59.3, U. S. Hwy. 380, in dead leaves of Nolina sp., 18 Oct. 1993, Annette Ramaley 9332B(UC 1475190). TEXAS: Brewster Co., Big Bend National Park, Sotol Vista, in dead leaves of Dasylirion leiophyllum Engelm., 20 May 1995, Annette Ramaley 9502 (UC 1475189).

Notes – Comminutispora agavaciensis is established to accommodate the distinctive combination of characters of this fungus, (a) the presence of plentiful interascal cells even at maturity, (b) the small, cylindric papilla that penetrates the host epidermis, which may crack, but remains in place, (c) immersed, unilocular ascomata, (d) the presence of a meristematic area in the small papilla forming periphyses at the time of ostiole formation, and (e) I-S-transversely septate ascospores which become muriform and eventually form separate tiny secondary ascospores that are released from the ascospore wall and fill the ascus.

Figures 1-3 – Comminutispora agavaciensis (BPI 802958). 1. Ascoma. Bar= 50 ~m. 2. Asci. Bar= 25 ~m. 3. Ascospores in various stages of division and some free secondary ascospores. Bar = 10 μm.