_Bowenia._ The large fronds of this genus (fig. 391) are peculiar in being bipinnate; they may reach a length of 2 metres and have a long slender petiole: the asymmetrical lamina of the segments, entire or deeply serrate, is attached by a very short stalk; the veins branch dichotomously[57] and diverge slightly. Both entire and serrate pinnae may occur on the same plant, but Chamberlain has revived André’s specific term _serrulata_ in preference to the generally adopted designation for the serrate forms, _B. spectabilis_ var. _serrata_[58]. [Illustration: Fig. 391. _Bowenia spectabilis_, frond. (From the _Encyclopaedia Britannica_.)] _Reproductive shoots_[59]. In _Cycas circinalis_, _C. Rumphii_, and other species the megasporophylls reach a considerable length and bear several lateral ovules each of which may be as large as a goose’s egg: the sterile distal end has the form of a spear-point with an irregularly serrate edge. In _C. revoluta_, _C. pectinata_, etc., the sterile part is deeply dissected and may break off (fig. 392, A) from the fertile portion of the sporophyll. The megasporophylls of _C. Riuminiana_ exhibit a striking variation in form (fig. 392, B, C); some are 15 cm. long with several ovules, while others, reduced to 8 cm., bear only two ovules and resemble the sporophylls of _Dioon_. In all other genera the megasporophylls are aggregated into cones, but in _Dioon_ the strobili are characterised by their more ovoid form and by the looser arrangement of the sporophylls (fig. 386, B), each of which consists of a horizontal stalk expanded distally into a broadly lanceolate upturned end covered with a thick felt of hairs and bearing at its base usually 2, rarely 5–6, ovules on cushion-like swellings. In _Dioon spinulosum_ the cones may be 50 cm. long. Between the cones of _Microcycas_, over 90 cm. long, and those of some Zamias, a few centimetres long, there are many intermediate forms. The large strobilus of an _Encephalartos_ reproduced in fig. 393, D, shows the convex ends of the sporophylls with a jagged edge, and in monstrous cones the marginal lobes may be abnormally developed and assume the appearance of pinnae[60]. Each megasporophyll bears two large ovules (fig. 393, B). In certain species of _Encephalartos_ the swollen ends of the sporophylls have a truncate centre like the flattened umbo of some Pines (fig. 392, D). The presence of two divergent spines is a peculiarity of the megasporophylls of _Ceratozamia_ (fig. 393, C): in _Macrozamia_ (fig. 394) the distal ends are prolonged as tapered processes. The surface of the strobilus of _Stangeria_ is formed by imbricate and rounded ends of sporophylls (fig. 392, H) not unlike the cone-scales of _Pinus excelsa_ or _P. cembra_. The megasporophylls of _Zamia_ are expanded into regular cushion-like hexagons with a flat central area (figs. 389, B; 395, I_b_). [Illustration: Fig. 392.