After producing spine primordia and trichomes (and glochids in Opuntioideae), the axillary bud SAM remains capable of further growth, either as a floral bud, a vegetative branch or as short-shoot. ... Axillary buds in some cacti are capable of more than producing only one flower and later one branch. ...
In contrast, in a small subgroup of Cactoideae (e.g. Coryphantha, Mammillaria), the growth zone is located directly below the axillary bud SAM, which consequently is stretched as the tubercle grows. In Mammillaria, the bud SAM always divides dichotomously and one of the two new SAMs is carried outward along with the tubercle tip while the other remains stationary, at the base of the tubercle.
Buxbaum (1958a) proposed that the evolution of dimorphic areoles in the tribe Cacteae occurred along two distinct lines. The first lineage shows a succession from Leuchtenbergia, which has elongated tubercles tipped by undifferentiated areoles, to Roseocactus (Ariocarpus fissuratus, A. kotschoubeyanus) with areoles forming an elongated furrow along the length of the tubercle with separate floral and spine-bearing regions (Anderson 1960), to Ariocarpus with separate floral and spine-bearing areoles and some species lacking spine-bearing areoles altogether (Anderson 1960).
不過, 在 The New Cactus Lexicon 對於 Leuchtenbergia 屬的敘述提到 "flower borne at the ventral edge of areoles of young tubercles, otherwise like those of Ferocactus.", 加粗字的那裡我就有點不太懂, 為什麼只有年輕的疣粒 "腹部 才會開花, 比較成熟的疣粒開花的位置就和 Ferocactus 屬一般 ( 在頂端 ) ?
UA 和 yongkucai 提到是從腋窩出芽, 不知是不是都是在嫁接的幼苗( 幼株 )才會發生那樣子的情況 ? 若是, 由 The new cactus lexicon 中的敘述, nirwa 推想, 是不是 Leuchtenbergia 屬的線狀長生點 ( meristem ) 可能會隨著年齡逐漸往疣粒的頂端推, 所以為什麼李姐找的圖都是從刺座長出的, 應該大都實生成熟株 ( 因為我在 google 找的開花圖看起來都是實生株 ).
按這裡註冊 
