IO4 



BRITISH FLORA 



entire, whorled, in fours, shorter than the flowers. 

 The lower bracts may be pectinate. The fruit is 

 hardly rounded. The plant is submerged. It 

 flowers from June to August, and is a herbaceous 

 perennial. 



Water Starwort (Callitriche vtrna, L. = C. 

 palustris, L.). The habitat of this plant is ponds, 

 ditches, sluggish streams. The habit is aquatic. 

 The stem is round in section, little branched, sub- 

 merged. The leaves are inversely ovate to spoon- 

 shaped, the floating ones forming a rosette, 3- 

 nerved, or rarely wanting, narrowed at the base, 

 with submerged, linear leaves. The flowers are 

 in the axils, male and female in opposite axils. 

 The bracts are white, straight, and soon fall, 

 being bent inwards. The fruit is nearly stalkless, 

 longer than broad, with parallel lobes, bluntly 

 keeled on the back, convex on the sides, united 

 below for half their length. There is a hollow 

 furrow which is not extended to the base. The 

 anther-stalks are very slender. The plant is 

 3-12 in. in height, flowering between April and 

 October, and is a herbaceous perennial. 



Callitriche stagnalis, Scop. The habitat of this 

 plant is ponds and ditehes. The habit is as in 

 the last. The leaves are all similar, narrow at 

 the base, inversely ovate to spoon-shaped, the 

 floating leaves forming a rosette, which, however, 

 may not develop. The flowers are as in the last, 

 with sickle-like, persistent bracts. In flower the 

 styles are erect and persistent, turned back in 

 fruit. The fruit is nearly stalkless, with lobes 

 winged on the back, twice as large as in C. verna, 

 and when dry pale in colour. The lobes are 

 slightly spreading. The plant is floating or sub- 

 merged. Flowers may be found between April 

 and September. The plant is a herbaceous annual 

 or perennial. 



Callitriche polynwrpha, Lonnr. The habitat of 

 this plant is watery places. In habit the plant 

 resembles C. slagnalis. The fruit, however, is 

 not so large and is hardly winged. The lower 

 leaves are linear, notched. The upper leaves are 

 roundly spoon-shaped, and form a rosette. The 

 flowers are as in the last, with sickle-like, per- 

 sistent bracts. The fruit is as small as in C. 

 verna. It is almost stalkless, with lobes scarcely 

 winged on the back, and keeled. The style is 

 erect in flower, turned back in fruit, very long, 

 2-3 times as long as the fruit. The plant is float- 

 ing or submerged. It is in flower between June 

 and September, and is a herbaceous annual or 

 perennial. 



Callitriche intermedia, Hoffm. (= C. hamulata, 

 Kutz.). The habitat of this plant is lakes and 

 streams, &c. The plant has the Starwort habit. 

 The leaves are linear, the upper broader in the 

 middle, the uppermost oblong, spoon-shaped. The 

 bracts overlap, and are hooked, and do not per- 

 sist. The styles are long, spreading, and at 

 length turned back over the side of the fruit. The 

 pollen is more or less round. The fruit is stalk- 

 less, with a blunt dorsal ridge, flat one side, 

 broader than long, the lobes are parallel with the 

 dorsal ridge, and there is a shallow furrow. The 



plant is floating or submerged. It flowers between 

 April and September, and is a herbaceous annual 

 or perennial. 



Callitriche obtusangula, Le Gall. The habitat 

 of this plant is ponds and ditches. The plant has 

 the Starwort habit. The leaves, which are all 

 inversely ovate, form a rosette. The bracts are 

 persistent. The styles are spreading, or erect, 

 and do not fall. The fruit is large, blunt, hardly 

 stalked. The lobes are parallel with the rounded 

 edges. The carpels are swollen, obtusely 3-angled 

 on the back. The plant is floating or submerged. 

 It is in flower between April and September, and 

 is a herbaceous annual or perennial. 



Callitriche truncafa, Guss. The habitat of this 

 plant is ditches. The leaves are all of the same 

 type, and are enlarged at the base, and linear. 

 They are all submerged, very blunt at the end, 

 and of a clear, green colour. There are no bracts. 

 The styles are bent back or spreading. The fruit 

 consists of 4 nearly equal lobes, and is shortly- 

 stalked, the lobes having a blunt dorsal ridge, 

 being keeled. The plant is floating or submerged. 

 It flowers between June and September, and is a 

 herbaceous annual or perennial. 



Callitriche autumnalis, L. The habitat of this 

 plant is lakes, especially in North Britain. The 

 leaves are all of the same type, enlarged below, 

 linear, dark-green, submerged, blunt at the end. 

 There are no bracts. The styles are spreading. 

 The fruit is stalkless, four times as large as in 

 C. verna, dark-brown, with one or two abortive 

 lobes. The carpels are keeled or winged, united 

 towards the axis only. The lobes have broad and 

 acute wings on the back. The plant is sub- 

 merged. It flowers between June and October, 

 and is a herbaceous annual or perennial. 



ORDER LYTHRACE^ 



Hyssop Loosestrife (Lythrum hyssopifolia, L.). 

 The habitat of this plant is moist places, often 

 liable to inundation, just where one might expect 

 to find Water Purslane, but it is very local. The 

 habit is prostrate, or ascending, spreading, simple 

 or branched. The leaves are alternate, linear to 

 lance-shaped, blunt. They are stalkless, and 

 wedge-shaped below, very narrow. The flowers 

 are small, solitary, pink or purplish, in the axils. 

 There are 2 minute, awl-like bracts. The calyx- 

 teeth are short, awl-like. The petals are oblong. 

 There are 6 stamens. The capsule is cylindrical. 

 The plant is 6-18 in. in height, and flowers be- 

 tween June and September, and is a herbaceous 

 perennial. 



ORDER EPILOBIACE.* 



Downy Willow Herb (Epilobiunt parviflorum, 

 Schreber). The habitat of this plant is ditches and 

 river- banks, watery places. The plant has the 

 willow-herb habit, or more or less that of a rosette 

 below, with erect stem. There are autumnal 

 stolons, with more or less stalkless, or stalked, 

 rosettes of leaves. The root is fibrous. The stem 

 is downy, round in section, branched above, or 



