The affinity of Dirinaceae and Roccellaceae with Graphidaceae was first indicated by Reinke[1045] and elaborated later by Darbishire[1046] in his monograph of Roccellaceae. The apothecia in some species of Dirina are ellipsoid rather than round; in several genera of Roccellaceae they are distinctly lirellate, and in Roccella itself some species have ellipsoid fruits. The fruticose thallus is predominant in Roccellaceae, but its evolution from the crustaceous type may be traced through Roccellina which is partly crustaceous and only imperfectly fruticose.
In most of the genera only one species is recorded. Roccella, represented by twelve species, is well known for its dyeing properties, and has a wide distribution. Like other Graphidineae they are mainly plants of warm regions, many of them exclusively maritime rock-dwellers.
The following synopsis of the genera is the one given by Darbishire in his monograph.
| Cortex fastigate, of palisade hyphae. | ||
| Spores colourless. | ||
| Hypothecium black-carbonaceous. | ||
| Apothecia round. | ||
| Thallus fruticose | 1. | Roccella DC. |
| Thallus crustaceous-fruticose | 2. | *Roccellina Darbish. |
| Apothecia lirellate | 3. | *Reinkella Darbish. |
| Hypothecium colourless. | ||
| Gonidia present under the hypothecium | 4. | *Pentagenella Darbish. |
| Gonidia absent from hypothecium | 5. | *Combea De Not. |
| Spores brown or brownish. | ||
| Medulla of parallel somewhat loose hyphae | 6. | *Schizopelte Th. Fr. |
| Medulla solid, black | 7. | *Simonyella Steiner. |
| Cortex fibrous, of parallel hyphae. | ||
| Apothecia round. | ||
| Hypothecium black-carbonaceous. | ||
| Apothecia with thalline margin | 8. | *Dendrographa Darbish. |
| Apothecia with proper margin | 9. | *Roccellaria Darbish. |
| Hypothecium colourless | 10. | *Darbishirella A. Zahlbr. |
| Apothecia lirellate | 11. | *Ingaderia Darbish. |
Subseries 3. Cyclocarpineae
This last subseries includes the remaining twenty-nine families of Ascolichens. They are very varied both in the fungal and the algal symbionts. The fruit is more or less a discoid open apothecium. The gonidia belong to different genera of Myxophyceae and Chlorophyceae, but the most frequent are Protococcaceae. Families are based largely on thalline structure.
XXIII. Lecanactidaceae
By many systematists this family is included under Graphidineae on account of the fruit structure which in some of the forms is carbonaceous and almost lirellate, and also because the algal symbiont is Trentepohlia. The thallus is primitive, being thinly crustaceous and non-corticate; the apothecium has a black carbonaceous hypothecium in two of the genera, Lecanactis and Schismatomma (Platygrapha); in the third genus, Melampydium, it is colourless. The latter is monotypic, and the spores become muriform. In the other genera they are elongate and multi-septate.
| Apothecia with prominent proper margin | 1. | Lecanactis Eschw. |
| Apothecia with thin proper margin | 2. | *Melampydium Müll.-Arg. |
| Apothecia with thalline margin | 3. | Schismatomma Flot. |