This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Herbs with basal or alternate or opposite leaves. Flowers perfect or polygamo-dioecious, solitary, racemose, cymose or paniculate. Calyx 5-lobed or 5-parted (rarely 4-12-lobed or parted), free, or adnate to the ovary, usually persistent. Petals usually 4 or 5, rarely none. Stamens equal in number or twice as many as the petals, in apetalous species as many or twice as many as the calyx-lobes, peri-gynous or epigynous; filaments distinct. Disk generally present. Carpels 1-several, often 2, distinct or united, mostly fewer than the stamens; styles as many as the carpels or cavities of the ovary. Fruit a capsule or follicle. Seeds commonly numerous; endosperm generally copious, fleshy; embryo small, terete.
About 90 genera and 650 species, of wide geographic distribution, mainly natives of the temperate zones, rare in the tropics.
Large herbs; leaves 3-ternate; flowers polygamous. | 1. | |
Small herbs; leaves simple, entire, toothed or cleft, or 3-foliolate. | ||
Placentae axial; carpels equal or nearly so. | ||
Stamens 10. | ||
Calyx-tube only slightly developed, unchanged at maturity; or if slightly accrescent, then | ||
flat or flattish and plants acaulescent. | ||
Leaves opposite, except sometimes on flower-stalks. | 2. | Antiphylla. |
Leaves alternate, sometimes all basal. | ||
Plants caulescent. | 3. | Leptasea. |
Plants acaulescent. | ||
Corolla essentially regular, the petals about equal in length and shape. | ||
4. | Micranthes. | |
Corolla irregular, except sometimes that of the terminal flower, three of the | ||
petals with blades of an ovate-lanceolate or sagittate type, and two of them | ||
narrower and longer. | 5. | Hydatica. |
Calyx-tube well-developed, and accrescent, at maturity longer than the lobes. | ||
Plants without caudices, only producing annual flowering stems. | 6. | Saxifraga. |
Plants with perennial leafy caudices, often with offsets, the flowering stem very differ- | ||
ent from the caudex. | ||
Leaves of the caudex with lobed blades, the margins poreless. | 7. | Muscaria. |
Leaves of the caudex with serrate blades, each tooth with an encrusted pore. | ||
8. | Chondrosea. | |
Stamens 5. | ||
Calyx-lobes valvate; petals deciduous; seeds wingless. | 9. | Therofon. |
Calyx-lobes imbricated; petals persistent; seeds winged. | 10. |
♦Revised for this edition by Dr. John Kunkel Small.
Placentae almost basal; carpels very unequal. | 11. | Tiarella. |
Placentae parietal; carpels equal or nearly so. | ||
Flowers in elongated racemes or panicles. | ||
Petals entire or erose. | 12. | Heuchera. |
Petals pinnately cleft or parted. | 13. | Mitella. |
Flowers solitary and axillary to leaf-like bracts or 2-4 together and each subtended by a | ||
leaf-like bract. | 14. | Chrysosplcnium. |
 
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