NATURAL OKDEKS. 



265 



Genera. — Melothria, Momordica, Cucumis, Cucurbita, Sicyos. 



Fig. 187, a, staminate flower of Cucumis sativus laid open, showing the stamens 

 attached to the petals, and sinuous anthers ; c, 5-toothed calyx ; p, petals united ; 

 8, stamen separated ; b, a pistillate flower, with the calyx adherent to the ovary ; 

 St, stigma ; se, a seed cut vertically ; e, the embryo separated. 



459. Crassulace^, the Ilouse-leek Tribe. — Succulent lierls or 

 shricbs. Leaves entire or pinnatiiid. Flowers in cymes or 

 racemes, sessile. Se_pals 3-20, more or less united, i^ersistent. 

 Petals as many as the sepals, usually distinct. Stamens in- 

 serted with the petals and equal to them in number, or twice 

 as many. Carpels as many as the petals and opposite to them, 

 sometimes consolidated. Fruit consisting of several follicles. 

 Seeds variable in number ; emhryo straight, in thin albumen. 



Genera. — Bryophyllurf^ Sedum, Sempervivum, Penthorum. 



460. SAxiFKAGACEiE, tlie Saxifrage Tribe. — Herbs or shrubs. 

 Leaves alternate or opposite. Sejpcds 4 or 5, more or less united. 

 Petals as many as the sepals, or wanting. Stamens 5-10, pe- 

 rigynous. Ovary usually consisting of 2 carpels, united at the 

 base, distinct at the apex ; stigmas sessile. Fruit capsular, 1 

 or 2 celled. Seeds numerous, minute ; embryo straight, in fleshy 

 albumen. The three sub-orders are, 



1. Saxifrages. — Small herbaceous plants. Petals imbricate 

 in aestivation. Capsule 2-celled, with the placentae in the axis, 

 or 1-celled, with parietal placentae. 



2. Hydrangea. — Shrubs. Petals valvate in aestivation. Cap- 

 sule 2-celled ; the styles or stig- Pi„ ^^^ 

 mas distinct or united. Stamens 

 sometimes numerous. 



3. Philadelphes. — Shrubs. 

 Petals convolute in [estivation. 

 Capsule 3 or 4 celled ; styles 

 more or less united. Stamens 

 usually numerous. 



a. Properties : astringent. 



Genera. — 1. Saxifrages — Saxifraga,Le- 

 puropetalon, Chrysosplenium, Heuchera, 

 Llitella, Tiarella. 2. Hydrange.e — Hydran- 

 gea, Decumaria. 3. Philadelpheje — Phila- 

 delphus, Itea, 



Fig. 188, a. Hydrangea virens ; b, a 

 seed-vessel of H. hortensis ; c, its seed ; d, 

 a section of it. 



461. Hamamelaces, ^A^ Witch-Hazel Tribe. — Shrubs ov sm£ill 

 trees. Leaves simple, alternate. Flowers often polygamous, 

 axillary. Calyx 4 or 5 oleft. Petals alternate with the seg- 

 ments of the calyx, valvate in aestivation. Stamens 8, 4 alter- 

 nate with the petals, and fertile ; the other 4 are opposite and 

 fitci-ile. Ovary adherent; ovide solitary, suspended; stylefi 2. 



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