BOTANY PoLYGALEJE Polygala oxyptera, Reichb. CARYOPHYLLE.K Silene conlca, L. noctiflora, L. Arenaria (Alsine) tenuifolia, L. LEGUMINOSJE Trifolium ochroleucum, L. Astragalus hypoglottis, L. Hippocrepis comosa, L. Vicia (Ervum) gracilis, Lo'ucl. lilvatica, L. Lathyrus aphaca, L. silvestris, L. ROUCES Prunus cerasus, L. CRASSULACEJE Sedum fabaria, Koch ONAGRARIE./E Epilobium roseum, Schreb. UMBELLIFERJE Smymlum olusatrum, L. Bupleurum rotundifolium, L. Apium graveolens, L. Carum segetum, Benth. (Bunium) bulbocastanum, Koch Sesseli libanotis, Koch (Enanthe Lachenalii, Gmel. Caucalis daucoides, L. RUBIACE.E Galium Witheringii, Sm. erectum, Huiis. VALERIANEJE Valeriana officinalis, L. Valerianella auricula, DC. (rimosa, Bast.) COMPOSITE Filago spathulata, Presl Senecio (Cineraria) campestris, DC. Centaurea calcitrapa, L. Crepis biennis, L. taraxacifolia, Thutll. MONOTROPEJE Hypopithys multiflora, Scop. PRIMULACE^ Anagallis cxrulea, Schreb. CONVOLVULACEJE Cuscuta europaea, L. SCROPHULARINE. Verbascum blattaria, L. Antirrhinum orontium, L. Linaria spuria, Miller Melampyrum arvense, L. cristatum, L. OROBANCHEJE Orobanche major, L. minor, Suit. LABIATE Mentha pulegium, L. Ajuga chamaepitys, Schreb. CHENOPODIACEJE Chenopodium vulvaria, L. ficifolium, Sm. hybridum, L. POLYGON AC EJE Polygonum maculatum, Dyer et Trimen SANTALACEJE Thesium linophyllum, L. (humifusum, DC.) EUPHORBIACE.S Euphorbia platyphyllos, L. ORCHIDEJE Cephalanthera pallens, Rich. Orchis ustulata, L. Herminium monorchis, Br. IRIDE/E Iris foetidissima, L. CYPBRACE. Carex Jioica, L. stricta, Good. xanthocarpa, Degl. (1 hybrid) GUMMBJI Phleum phalaroides, Koel. Bromus racemosus, L, Brachypodium pinnatum, Beauv. Hordeum silvaticum, Huds. (Elymus europxus, L.) DISTRICT III. THE THAME The very small portion of the extreme west of the county which is in this district forms a tongue-like protrusion into Buckinghamshire, being bounded by that county on all sides but the east, where the Colne district forms the boundary. The small tributary streams of the Thame, rising near Tring, are intercepted by the reservoirs which supply the Grand Junction Canal, all of which are in this district. The Thame soon leaves our county, and, flowing westward north of Aylesbury to below Dorchester in Oxfordshire, there unites with the Thames ; or, as Chauncy says (Hist. Antiq. Herts), ' then congratulates the Isis ; but both emulating each other for the name, and neither yielding, they are complicated by that of Thamisis.' The district lies high : a mile north of Tring is the summit-level of a system of canals which radiate to the north, west, south-west, and south-east. The Chalk terminates near the 53
