Lemna. | CLI, LEMNACEZ (BROWN). 203 
of the River Loge, and in nearly stagnant streamlets near Ambriz, Welwitsch, 208. 
Loanda ; in deep ponds near Bemposta, Welwitsch, 205 partly! Icolo e Bengo; in 
a lake called Lugoa de Quilunda, near Prata, and in lakes in the Libongo district, on 
the left bank of the River Lifune, Welwitsch, 218. Mossamedes ; in deep ponds at 
the mouth of the River Giraul, and near Aguada, Welwitsch, 207 ! 
Mozamb. Dist. German East Africa: Usambara; Lutindi, Holst, 3441! 
Usaramo ; Bagamoyo, Hildebrandt, 1279! Portuguese East Africa: Quilimane 
Stuhlmann (ex Hegelmaier). 
Widely distributed through the warmer parts of the earth. 
This species is very similar to L. minor, Linn., and not easily distinguishable in 
the dried state without careful examination. ‘The fronds, however, are smaller, and 
the root-cap more acute than in Z. minor, and the root-sheath has a wing on each 
side of it, which is wanting in Z. minor. 
d. L. zquinoctialis, Welw. Apont. 578. Fronds very small, 
4-% lin. long, 4-4 lin. broad, elliptic or elliptic-obovate, “somewhat 
fleshy, slightly convex, obtusely keeled longitudinally on the upper face, 
ellipsoid at both ends, minutely but distinctly corniculate. Flowers 
emerging from a marginal slit” (Welwitsch). Root solitary from near 
the basal end of the underside of each frond. Fruit ellipsoid, ribbed. 
—Hegelmaier, Monogr. Lemn. 142; Rendle in Cat. Afr. Pl. Welw. ii. 
91. L. angolensis, Welw. ex Hegelmaier in Journ. Bot. 1865, 112 ; 
Hegelmaier, Monogr. Lemn. 141, t. 7, figs. 9-17, and in Engl. Jahrb. 
xxi. 296; Durand & Schinz, Conspect. Fl. Afr. v. 484; Engl. Pfl. Ost- 
Afr. C. 422. 
Nile Land. British East Africa : Niamniam ; at Makporru Hill, Schwein- 
Surth, 3740! at the River Ibba, near Nyanye, Schweinfurth, 3986! Uganda ; Man- 
yonyo (Manjonga), Stuhlmann (ex Hegelmaier). 
Lower Guinea. Angola: Loanda; in deep ponds near the town of Loanda 
Welwitsch, 206 ! 
In the dried state I find the longitudinal keel on the upper surface to be much 
more evident in Schweinfurth’s specimens than in those of Welwitsch. 
2. WOLFFIA, Horkel; Benth. et Hook. f. Gen. Pl. iii. 1001. 
Flowers seated in a cavity or in two separate cavities in the upper 
surface of the frond, without a spathe, microscopic, rarely seen. 
Stamen 1; anther 1-celled, opening by a slit across the top and the 
valves becoming reflexed.—-Fronds small or minute, thin and flat, or as 
thick as broad, subglobular, hemispherical, ellipsoid, elliptic, oblong or 
linear, entire or rarely toothed at the margin or end of the frond, 
entirely destitute of roots, but in two species the lower lip of the 
cavity from which the young frond emerges is produced into a 
moderately long flat hyaline process that might easily be mistaken for 
a root; this process is a development of the stalk by which the young 
frond is attached to its parent, and which elongates extraordinarily 
after their separation. 
Species 12, widely distributed in all the warm and temperate parts of the earth. 
