EXOGENS. 55 



endocarp, 3-seeded. Shrubs or Trees. Lvs. simple, alt., persistent. 

 2gen., both trop. Am. 1. Synzyganthera. Pis. (f . Shrub. 2 species. 

 2. Lacistema. Fls. ? S^ (f*. Trees or shrubs, few species. 



Ord. 14. Geissolomaceae. — Consisting of a single genus and 

 species, Geissoloma mnrc/indta, a shrub with red monochlamydeous 

 fls. surrounded by bracts ; perianth-segments 4, stamens 8. Close to 

 Penseacese (whicti see). Mts. S. W. Af. 



Ord. 15. PenseacesE.^Pls. § . Monochlamyd. Perianth col- 

 ored, 4-lobed, isostemonous, accrescent. Ova. free, 4-celled, 4-valved. 

 Boll 4-valved. Heath-lilse evergreen Shrubs, S. Af. 2 Tribes ; types 

 given : Tribe 1. Ov. 4 in each cell, 2 ascending, 2 pend. 1. Endo- 

 nema. Tribe 2. Ov. 2 in each cell, erect. 1. Penaea ; 2. Sarco- 

 colla squamosa (Penaea SarcocoUa) yields the resin Sakcocol of 

 pharmacy. Pis. clustered in the axils of large colored bracts, which 

 yield the resin. 



Ord. 16. Euphorbiacese.^ — Pis. diclinous, mono- rarely dichlamyd., 

 or achliimyd. Infl. various. Ova. free, 3-l-oo -celled. Pr. (boll) of 

 3 cocci, rarely a berrj'. Perisperm present, fleshy. Emb. axillary. 

 Large or small Trees, Under shrubs, or Herbs, of very various habits, 

 with milky acrid or watery juice. 230 known gen. ; 2600 species. 11 

 Tribes : 



Tribe 1. Buxineae. — Pis. J^. Ovarian cells geminate-ovuled. In- 

 volucre 0. (^ tetrandrous. 5 gen. 1. Biixus, Box. Shrubs or 

 small trees ; lvs. evergreen. Fls. in axillary clusters, 1 9 ^it top of 

 each cluster. Sev. spec, Eur., Asia. B. sempervirens. Common B., 

 20°-30° high ; wood valuable ; dwarfed for gardens. B. baledrica, 

 60°-80° high ; lvs. larger, paler ; wood coarser. Medit. Islands, Asia 

 Minor. 2. Simmondsia (Brocchia) califhrniea, evergreen bush ; (^ 

 fls. clustered, 9 sol. ; fr. size of an acorn, edible. Cal. 



Tribe 2 — Ovarian cells 1-ovuled. Pis. involucrate ; involucre 2- 

 sexual, flower-like.. Infl.. cymose. ,^ fl. monandrous. Several gen. 



1. Euphorbia. Pis. described. Lesson XX. Very many species, 

 various in appearance and habit, except as to the fls. 30 species are 

 mere weeds in U. S. E. corollata, % herb, 2°-3° high ; involucre 

 white. Pig. 146. Can., TJ. S. E. margindta, herb, l°-3° high. 

 Involucre white ; lvs. white-margined. Western U. S. E. fulgens, 

 shrub, involucre bright red. Me.x. E. sptendens, shrub, stems cov- 

 ered with frightful prickles ; bracts large, red, like 2 petals below the 

 cup-like involucre. Mauritius. E. (Poinsettia) pulcherrima, thorn- 

 less shrub ; lvs. next below the fls. bright red, showy. Mexico. E. 

 phosphbrea, milky juice phosphorescent. Brazil. See Lesson 

 XXXII. E. grandidens, stem fleshy, leafless, like a tree-cactus. S. 

 Af. E. canariensis, similar, small. Canaries. 



Tribe 3. — Like last, but (^ fl. polyandrous. Only genus Dalech&m- 

 pia. Stem twining or scrambling to a great height. Involucre 2- 

 leaved, colored, showy. Tropics, both worlds. 



Tribe 4. — Ovarian cells 1-ovuled. Involucre 1-sexual. 16 sub- 

 tribels, many gen. and spec. Types only given here. 



1. iiiira crepitans (only species). Sand-box Tree, Monkey's Din- 

 ner-Bell. 30°-40° high ; lvs. resembling those of Poplar. Pis. $ J*. 

 Boll many-celled, flattened vertically, grooved, as large as an orange, 

 hard-shelled, exploding when ripe with a noise like a. pistol-shot. 

 Dried and emptied before ripening, it makes an elegant sand-box. 



