Crassulaceae
Annual or perennial herbs, sometimes small shrubs, with vegetative organs and often floral parts ± succulent, often reproducing by offsets or rhizomes. Stems prostrate to erect, sometimes with bulbils formed on them. Lvs opposite or alternate, usually simple, occasionally pinnate; stipules 0. Infl. usually variously cymose, often with many branches, sometimes paniculate; bracts usually ± persistent, sometimes caducous; fls actinomorphic, usually ⚥, rarely unisexual (spp. dioecious), (3)-4-20-(32)-merous, often secund. Sepals equal or unequal, free or connate, sometimes forming a tube. Petals free or connate, occasionally forming a tube. Stamens somewhat perigynous, as many as or twice as many as the petals, if twice petals then outer whorl antipetalous; anthers 2-locular, dehiscing longitudinally. Ovary superior; carpels free, as many as petals, 1-locular; ovules usually many, rarely few; styles free, usually prominent. Nectary scales usually present at base of carpels, sometimes 0. Fr. usually a group of follicles, sometimes a capsule, membranous or coriaceous, often surrounded by the persistent corolla. Seeds very small; endosperm usually present, sometimes 0.
Key
30-35 genera, 1400-1500 spp., widespread from cold temperate to tropical regions, especially southern Africa, Mediterranean region, Mexico.
A very large number of Crassulaceae are cultivated in N.Z., often in large specialist collections of succulents and cacti, although some, including a few genera not treated here, are also much more widely grown. The naturalised spp. nearly all originate from 4 regions; these are temperate Eurasia (Sedum spp.), Macaronesia (Aeonium spp.), southern Africa, especially the Cape province of South Africa (Cotyledon and Crassula spp.), and Mexico (Echeveria and Sedum spp.).
Apart from 3 Sedum spp. which are widespread and especially common in C. Otago, naturalised Crassulaceae are mostly confined to certain almost frost free coastal areas with summer droughts, and where there are steep open cliffs and rocky slopes and banks, especially on volcanic terrain. Such localities are: Auckland area, especially Rangitoto Id, Whakatane, Napier Hill, Wellington, Nelson, Port Hills and neighbouring parts of Banks Peninsula, Otago Peninsula and Harbour. All the naturalised spp. have xerophytic adaptations unlike the indigenous spp. which mainly inhabit wet places.
Owing to their succulence, members of this family present special problems for the taxonomist. Unannotated herbarium specimens are of very limited use, particularly if dried in the traditional way or with an additional preliminary immersion in boiling water, because of the shrinkage, distortion and lack of colour which result. For this account the descriptions were compiled almost entirely from fresh material, after which specimens were freeze-dried for the herbarium.
