A curious form, related to Hemitrichia, much as Oligonema is to Trichia. Related to both the genera first named, but distinct, in the peculiar sculpture, from Hemitrichia, and from Oligonema in that the threads are not entirely free. Professor Morgan's original determination, founded on Ohio materials is confirmed by material sent us by Professor Underwood from Alabama.
3. Trichia (Haller) Rost.
- 1768. Trichia Haller, Hist. Stirp. Helv., III., p. 114, in part.
- 1875. Trichia (Haller) Rost., Mon., p. 243.
Sporangia distinct, sessile or stipitate; capillitium of distinct elastic threads, free acuminate at each end, yellow or more rarely reddish or brown; spores generally yellow.
The trichias are easily recognized among their kind by their beautiful spirally wound, elastic capillitial threads, the elaters; these are entirely free, about 3–4 mm. in length, simple or only rarely branched, and generally acute at each extremity. The spiral bands, sometimes called taeniae, are generally very uniform in thickness, distance from each other, and pitch, and in many species are further reënforced by minute longitudinal plications running from one spiral to the next. Furthermore, the spirals may be smooth or spinulose the elater uniform throughout or enlarged betimes by nodes and swellings. Taken altogether, the trichias with the species of the genus next following exhibit the highest degree of differentiation attained by the Myxomycetes.
Most of the earlier authors, including Haller, used the generic name Trichia to cover a variety of forms. It is here used with the limits sketched by De Bary in 1859 and 1864 (Die Myxomyceten), and followed more exactly ten years later by his pupil, Rostafinski.
Key to the Species of Trichia
| A. Sporangia, in typical cases at least, wholly sessile. | |||||
| a. Gregarious; hypothallus none. | |||||
| i. Peridium brown or reddish brown. | |||||
| O Elaters smooth. | |||||
| OO Spirals even, regular | 1. T. inconspicua | ||||
| + Spirals irregular | 2. T. contorta | ||||
| ++ Elaters rough, spinescent | 3. T. iowensis | ||||
| ii. Peridium olivaceous or yellow. | |||||
| O Elaters smooth | 4. T. varia | ||||
| b. Hypothallus distinct; sporangia crowded; spores reticulate, banded, or netted. | |||||
| i. Spore-bands pitted | 6. T. persimilis | ||||
| ii. Spore-bands, narrow, plain | 7. T. favoginea | ||||
| iii. Spores covered by a delicate net | 5. T. scabra | ||||
| B. Sporangia stipitate. | |||||
| a. Hypothallus distinct | 8. T. verrucosa | ||||
| b. Hypothallus none; peridium checkered with pale reticulations. | |||||
| i. Brownish red or black | 10. T. botrytis | ||||
| ii. Olivaceous. | |||||
| O Elaters smooth | 11. T. subfusca | ||||
| OO Elaters rough | 12. T. erecta | ||||
| c. Peridium plain, shining | 13. T. decipiens | ||||
| d. Peridium plain, dull black | 14. T. lateritia | ||||
1. Trichia inconspicua Rostafinski.
[Plate III]., Figs. 5, 5 a, 5 b.