Dichotomous Key of the Deciduous Species of Stewartia
A. Styles 5, distinct; petioles widely winged, enclosing the lateral and terminal buds; floral bract
1. …………………………………………………………………………………………………….……………………S. ovata
A. Styles united, terminating in 5 or 6 stigmatic crests or arms; petioles narrowly winged, not
enclosing the lateral and terminal buds; floral bracts 2. ………………………………………..…………….B.
B. Stamens with purplish filaments and bluish anthers; capsules dehiscent by the outward
folding of the valve margins, the apices of the valves ± coherent; seeds angular. ………………..
…………………………………………………………………………………………………………S. malacodendron
B. Stamens with whitish filaments and yellow or orange anthers; capsules apically
dehiscent, the valves spreading apart from the apex; seeds plano-convex. …………….………..C.
C. Floral bracts about equalling or longer than the calyx; small or large trees or
shrubs with smooth or fissured bark; young branches usually terete, not
zigzagged. ……………………………………………….……………………………………………………….…D.
D. Ovaries and/or capsules subglobose, completely glabrous or pubescent only at
the very base.…………………………………………………………………………………………………E.
E. Ovaries and/or capsules completely glabrous; 2 ovules or seeds per locule;
bark on older branches smooth and mottled. …………………………………. S. serrata
E. Ovaries and/or capsules pubescent only at the very base; 4 ovules or seeds per
locule; bark on older branches finely fissured. ………………………………..S. rostrata
D. Ovaries and/or capsules conical, pilose or appressed-pubescent over the entire
surface……………………………………………………..…………………………………………………….F.
F. Sepals oblong to ovate with acute apices. …………………………………..……………G.
G. Floral bracts ovate, subequal to the sepals; styles 6-8 mm. long; seeds 7-9 mm. long. ………………………………………………………………………………S. sinensis
G. Floral bracts oblong; conspicuously longer than the sepals; styles 3-4 mm. long; seeds 5-6 mm. long……………………………………………………………………………………………………………………..………………………………………………………………………..……… S. monadelpha
F. Sepals ovoid with rounded, ciliate apices……………………………………………………… ………………………………………………………………………………………………… S. × henyrae
C. Floral bracts conspicuously shorter than the calyxl; small trees with smooth, mottled
bark; young branches usually compressed and zigzagged, rarely terete ………………………………………………………..…S. pseudocamellia
Key from Stephen A. Spongberg, 1974, A Review of Deciduous-Leaved Species of Stewartia (Theaceae), Journal of the Arnold Arboretum 55: 182-214.