The plants growing on chalk, are: Seligeria calcarea, on inclined faces of chalk pits, and occasionally on detached chalk. Seligeria calcicola, in similar situations on Woolsonbury. This is nearly allied to Seligeria pusilla, and has the capsule always ovate. Anacalypta caespitoso in some seasons is in plenty on Woolsonbury. Only two localities are known in Sussex, and it is not found elsewhere in Britain. Bryum intermedium is frequent in chalk pits, and remarkable for having the fruit on the same tuft in all stages of maturity. Encalypta streptocarpa, Woolsonbury, under beech trees. Neckera crispa, on Woolsonbury and Newtimber; in fruit on the first hill. Cylindrothecium Montagnei, Saddlescombe. Rhyncostegium depressum, Newtimber woods. Hypnum polymorphum, Patcham embankment. Hypnum chrysophyllum, common everywhere. Eurynchium circinnatum, Clayton.
The clay summits of the hills, as at Woolsonbury, give Phascum alternifolium and Weissia mucronata, and Physcomitrium fasciculare on Pyecombe downs. Racomitrium canescens is frequent in similar localities, and fruited on Woolsonbury in December, 1858. Tortula subulata and Eurynchium hians are also frequent, the latter differing from Eurynchium Swartzii, its near ally, in its wider, not acuminate, leaves.
The stiff soils of the hills furnish Phascum rectum, Phascum curvicollum, Astomum crispum, Gymnostomum microstomum, Pottia minutula, Anacalypta lanceolata, Didymodon luridus, Tortula convoluta, also Phascum bryoides in disused roads.
A rivulet at Grin Gap, near Newhaven, with its miniature ravine, gives Webera albicans, in fruit, Trichostomum topnaceum, and Hypnum riparium.
On the cliffs, east of Brighton, are found Acaulon triquetrum, the only British locality for this; also, Gymnostomum tortile, the var ß subcylindricum of which occurs on a hill near Greenway Station, Phascum curvicollum, Pottia cavifolia, Trichostomum mutabile, and Trichostomum crispulum. Anacalypta Starkeana, ß brachyodus, are all frequent, and Webera carnea, at Black Rock.
The sides of Woolsonbury have numerous species, as follows;—Phascum bryoides var γ, Archidium phascoides, Fissidens adiantoides, Dicranum palustre, Hypnum molluscum, Brachythecium glareosum, Bryum bimum, Bryum pseudo-triquetrum, Bryum roseum, and Bryum Billarderii; this last plant is exceedingly rare. It is the only known British locality, and it is not known to have been gathered elsewhere north of the Colosseum at Rome.
Brachythecium campestre is common in fields among grass, differing from Brachythecium rutubulum by its gradually tapering, not suddenly acuminate leaves. Bryum capillare ß flaccidum is found in a field in Newtimber valley. On walls Tortula vinealis, Tortula revoluta, Tortula rupestris, Grimmia pulvinata, Orthotrichum saxatile, Orthotrichum diaphanum, and Rhyncostegium tenellum, are luxuriant; but Bryum sanguineum is rare.
In Poynings springs Mnium affine and Hypnum filicinum are frequent. In the stubble fields at Aldrington are found Acaulon Florkeanum and Acaulon muticum, and in the near hedge-banks, Anacalypta Starkeana, Tortula insulana, Bryum Donianum, Scleropodium illecebrum. Once, in November, 1858, the very rare fruit of Eurynchium piliferum was gathered.
Around Aldrington Basin are seen Tortula ruralis, Tortula squarrosa, Trichostomum flavo-virens, Pottia Heimii, Pottia cavifolia δ gracilis, Physcomitrium pyriforme, Bryum cernuum, Bryum caespiticium, Bryum inclinatum, Bryum atropurpureum, and Rhyncostegium megapolitanum; also fertile Brachythecium albicans and Camptothecium lutescens.
In woods are Bryum torquescens, Orthotrichum Lyellii, Orthotrichum Ludwigii, Orthotrichum rupestre, Mnium hornum, Mnium rostratum, Mnium undulatum, Anomodon viticulosus, Neckera pumila, Neckera complanata, Isothecium myurum, Leucodon sciuroides, Cryphaea heteromalla, Leptodon Smithii, (fruiting at Poynings), Plagiothecium denticulatum, Plagiothecium sylvaticum, Eurynchium Swartzii, and all the species of Hylocomium: the last mentioned abundantly, with capsules, at Clayton. On detached ash trees at the feet of the hills, Orthotrichum tenellum, Orthotrichum pulchellum, and Tortula papillosa are not unfrequent. On beech stems about Woolsonbury, Zygodon viridissimus fruits freely, and a most diminutive state of Schistidium apocarpum is seen.